Method for performing action according to lbt type in unlicensed band in wireless communication system and user equipment using same

ABSTRACT

The present invention provides a method, performed by a user equipment (UE), for performing an action according to the type of listen before talk (LBT) in an unlicensed band, the method comprising the steps of: obtaining, from a base station, information about an LBT type and information about a physical uplink shared channel (PUSCH) starting position through an uplink (UL) grant; performing, on the basis of the obtained LBT type, an action according to the LBT type; and transmitting a PUSCH on the basis of the information about the PUSCH starting position after performing the action according to the LBT type, wherein the information about the PUSCH starting position indicates the position of any one of a plurality of PUSCH starting position candidates.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to wireless communication, and morespecifically, to a method for performing an operation depending on anLBT type in an unlicensed band and a user equipment using the method.

Related Art

3rd generation partnership project (3GPP) long-term evolution (LTE) is atechnology for enabling high-speed packet communications. Many schemeshave been proposed for the LTE objective including those that aim toreduce user and provider costs, improve service quality, and expand andimprove coverage and system capacity. The 3GPP LTE requires reduced costper bit, increased service availability, flexible use of a frequencyband, a simple structure, an open interface, and adequate powerconsumption of a terminal as an upper-level requirement.

As more communication devices require larger communication capacity, theneed for enhanced mobile broadband (eMBB) communication arises. Inaddition, massive machine type communication (MTC) that provides variousservices anytime anywhere by connecting multiple devices and things isalso one of main issues to be considered in next-generationcommunication. Furthermore, ultra-reliable and low latency communication(URLLC) that takes services/user equipment (UE) sensitive to reliabilityand latency into account is also under discussion. In this manner,introduction of a next-generation radios access technology inconsideration of eMBB, massive MTC, URLLC, and the like is underdiscussion, and such a new radio access technology may be called a newradio access technology (NR) for convenience.

In millimeter wave (mmW) bands, wavelengths become short and thus aplurality of antennas can be installed in the same area. For example, awavelength is 1 cm in a 30 GHz band, and a total of 100 antenna elementscan be installed in a 2-dimensional arrangement on a panel in 5×5 cm² atintervals of 0.5λ (wavelength). Accordingly, coverage is increased orthroughput is improved by increasing a beamforming gain using aplurality of antenna elements in mmW bands.

In this case, independent beamforming is possible for each frequencyresource if a transceiver is provided such that transmission power andphase can be controlled per antenna element. However, installation oftransceivers for all of 100 antenna elements is inefficient in terms ofprice. Accordingly, a method of mapping a plurality of antenna elementsto one TXRU and controlling a beam direction using an analog phaseshifter is considered. Such an analog beamforming method cannot providefrequency selective beaming because only one beam direction can begenerated in the entire band.

As an intermediate form of digital beamforming and analog beamforming,hybrid beamforming having B transceivers fewer than Q antenna elementsmay be considered. In this case, the number of directions of beams thatcan be simultaneously transmitted is limited to B or less although itdepends on methods of connecting the B transceivers and the Q antennaelements.

Physical channel structures of NR and/or characteristics related theretomay differ from those of legacy LTE according to inherentcharacteristics of NR. For efficient operations of NR, various methodscan be proposed.

SUMMARY

The present disclosure provides a method for performing an operationdepending on an LBT type in an unlicensed band in a wirelesscommunication system and a user equipment using the method.

In an aspect, a method for performing an operation depending on a listenbefore talk (LBT) type by user equipment (UE) in an unlicensed band isprovided. The method may comprise acquiring, from a base station,information about the LBT type and information about a physical uplinkshared channel (PUSCH) starting position through an uplink (UL) grant,performing the operation depending on the LBT type on the basis of theacquired LBT type and transmitting a PUSCH on the basis of theinformation about the PUSCH starting position after execution of theoperation depending on the LBT type, wherein the information about thePUSCH starting position is information indicating any one of a pluralityof PUSCH starting position candidates.

The information about the LBT type may indicate one of LBT type 1, LBTtype 2, and LBT type 3, the UE performs random back-off based LBT in theLBT type 1, the UE performs LBT without random back-off in the LBT type2, and the UE does not perform LBT in the LBT type 3.

A first uplink and a second uplink may be scheduled for the UE, and theUE performs LBT on the basis of a gap between the first uplink and thesecond uplink.

A downlink and an uplink may be alternately scheduled in a channeloccupancy time (COT) acquired by the UE.

A first downlink may be scheduled for the UE after scheduling of thefirst uplink and the second uplink is scheduled for the UE afterscheduling of the first downlink in the COT, and the LBT type isdetermined differently on the basis of whether transmission of the firstdownlink has been performed.

When multiple link transmissions are scheduled in a channel occupancytime (COT), based on a size of a transmission bandwidth of a previouslink, a transmission bandwidth of a following link may be limited.

The links may be uplinks or downlinks, a first downlink, a first uplink,and a second downlink are sequentially scheduled in the COT in a timedomain, and a transmission bandwidth of the first uplink is determinedon the basis of a size of a transmission bandwidth of the firstdownlink.

The UL grant may include start and length indicator value (SLIV)information, the SLIV information indicates a starting symbol index andthe number of symbols constituting the PUSCH, a symbol indicated by theSLIV information is symbol #K, and K is a positive integer.

The plurality of PUSCH starting position candidates may be at least oneof a first PUSCH starting position candidate set and a second PUSCHstarting position candidate set, the first PUSCH starting positioncandidate set includes symbol #(K-N)+16 μs, symbol #(K-N)+16 μs+TA,symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA, and symbol #K, the secondPUSCH starting position candidate set includes symbol #K, symbol #K+16μs, symbol #K+16 μs+TA, symbol #K+25 μs, and symbol #K+25 μs+TA, and Nis a value based on a subcarrier spacing.

The UE may determine a transport block size of the PUSCH on the basis ofassociation between the starting symbol index indicated by the SLIVinformation and a reference symbol index when the PUSCH startingposition is indicated.

The reference symbol index may be symbol #(K-N) when the PUSCH startingposition is between symbol #(K-N) and symbol #K, and the referencesymbol index is symbol #K when the PUSCH starting position is betweensymbol #K and symbol #(K+N).

CP extension may be applied to a gap between the PUSCH starting positionand a next symbol boundary on the basis of a subcarrier spacing.

The UE may implement at least one advanced driver assistance system(ADAS) function on the basis of a signal for controlling movement of adevice, the UE receives user input and switches a driving mode of adevice from a self-driving mode to a manual driving mode or switches thedriving mode from the manual driving mode to the self-driving mode.

The UE may autonomously travel on the basis of external objectinformation, the external object information including at least one ofinformation on presence or absence of an object, position information ofan object, information on a distance between the device and an object,and information on a relative speed of the device with an object.

In another aspect, a UE is provided. The UE may comprise a memory, atransceiver and a processor operably connected to the memory and thetransceiver, the processor is configured to: acquire, from a basestation, information about a listen before talk (LBT) type andinformation about a physical uplink shared channel (PUSCH) startingposition through an uplink (UL) grant, perform an operation depending onthe LBT type on the basis of the acquired LBT type and transmit a PUSCHon the basis of the information about the PUSCH starting position afterexecution of the operation depending on the LBT type, the informationabout the PUSCH starting position is information indicating any one of aplurality of PUSCH starting position candidates.

In other aspects, a processor for a wireless communication device in awireless communication system is provided. The processor may cause thewireless communication device to: acquire, from a base station,information about a listen before talk (LBT) type and information abouta physical uplink shared channel (PUSCH) starting position through anuplink (UL) grant, perform an operation depending on the LBT type on thebasis of the acquired LBT type and transmit a PUSCH on the basis of theinformation about the PUSCH starting position after execution of theoperation depending on the LBT type, the information about the PUSCHstarting position is information indicating any one of a plurality ofPUSCH starting position candidates.

According to the present disclosure, a base station can implicitlyindicate, to a UE, whether to perform LBT and an LBT type if LBT isperformed. Accordingly, PUSCH transmission based on various LBT types(e.g., LBT type 1, LBT type 2, and LBT type 3) can be stably instructed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates another example of a wireless communication system towhich technical features of the present disclosure are applicable.

FIG. 2 illustrates an example of a frame structure to which thetechnical features of the present disclosure are applicable.

FIG. 3 illustrates another example of a frame structure to which thetechnical features of the present disclosure are applicable.

FIG. 4 shows an example of a resource grid to which technical featuresof the present disclosure can be applied.

FIG. 5 schematically illustrates an example of a frame structure basedon a structure in which a data channel and a control channel aretime-division-multiplexed (TDMed).

FIG. 6 schematically illustrates the hybrid beamforming structure interms of TXRUs and physical antennas.

FIG. 7 schematically illustrates an example of the beam sweepingoperation for the synchronization signal and system information in adownlink transmission process.

FIG. 8 is a flowchart of a method for performing an operation dependingon an LBT type in an unlicensed band according to an embodiment of thepresent disclosure.

FIG. 9 schematically illustrates an example of UL #1 and UL #2 scheduledas consecutive UL bursts having a time-domain gap within a COT.

FIG. 10 schematically illustrates an example of UL #1 and UL #2scheduled as consecutive UL bursts having a time-domain gap within a COTwith different grants.

FIG. 11 schematically illustrates an example of multiple DL or ULtransmissions during multiple DL/UL switching within a COT acquired by agNB.

FIG. 12 schematically illustrates an example of transmission duringmultiple DL/UL switching in a DL #1-UL #1-DL #2 structure within a COTacquired by a gNB.

FIG. 13 schematically illustrates an example of transmission duringmultiple DL/UL switching in a UL #1-DL #1-UL #2 structure within a COTacquired by a UE.

FIG. 14 schematically illustrates an example of transmission duringmultiple DL/UL switching in a DL #1-UL #1-DL #2 structure within a COTof a gNB.

FIG. 15 schematically illustrates an example of PUSCH starting positioncandidates considering an LBT type and a subcarrier spacing.

FIG. 16 is a flowchart of a method for performing, by a UE, an operationdepending on an LBT type in an unlicensed band according to anembodiment of the present disclosure.

FIG. 17 is a block diagram illustrating an example of an apparatus forperforming, by a UE, an operation depending on an LBT type in anunlicensed band according to an embodiment of the present disclosure.

FIG. 18 is a flowchart of a method for indicating an LBT type by an eNBaccording to an embodiment of the present disclosure.

FIG. 19 is a block diagram illustrating an example of an apparatus forindicating an LBT type by an eNB according to an embodiment of thepresent disclosure.

FIG. 20 illustrates a UE for implementing embodiments of the presentdisclosure.

FIG. 21 illustrates a UE for implementing embodiments of the presentdisclosure in more detail.

FIG. 22 illustrates a network node for implementing embodiments of thepresent disclosure.

FIG. 23 illustrates an example of a signal processing module structurein a transmission apparatus.

FIG. 24 illustrates another example of a signal processing modulestructure in a transmission apparatus.

FIG. 25 shows examples of 5G usage scenarios to which the technicalfeatures of the present document can be applied.

FIG. 26 illustrates an AI device 100 according to an embodiment of thepresent disclosure.

FIG. 27 illustrates the AI server 200 according to an embodiment of thepresent disclosure.

FIG. 28 illustrates an AI system 1 according to an embodiment of thepresent disclosure.

FIG. 29 illustrates physical channels used in 3GPP systems and generalsignal transmission.

FIG. 30 schematically illustrates a synchronization signal and PBCHblock (SS/PBCH block).

FIG. 31 illustrates a method of acquiring timing information by a UE.

FIG. 32 illustrates an example of a system information acquisitionprocess of a UE.

FIG. 33 illustrates the random access procedure.

FIG. 34 illustrates the power ramping counter.

FIG. 35 illustrates the concept of a threshold of SS blocks for RACHresource association.

FIG. 36 illustrates a parity check matrix represented by a protograph.

FIG. 37 illustrates an example of an encoder structure for polar code.

FIG. 38 schematically illustrates an example of an encoder operation forthe polar code.

FIG. 39 is a flowchart illustrating an example of performing an idlemode DRX operation.

FIG. 40 schematically illustrates an example of the idle mode DRXoperation.

FIG. 41 is a flowchart illustrating an example of a method of performinga C-DRX operation.

FIG. 42 schematically illustrates an example of the C-DRX operation.

FIG. 43 schematically illustrates an example of power consumption inresponse to a UE state.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, terms or abbreviations which are separately defined can bedefined in 3GPP TS 36 series or TS 38 series.

FIG. 1 illustrates another example of a wireless communication system towhich technical features of the present disclosure are applicable.Specifically, FIG. 1 shows a system architecture based on a 5G new radioaccess technology (NR) system. The entity used in the 5G NR system(hereinafter, simply referred to as “NR”) may absorb some or all of thefunctions of the entities introduced in FIG. 1 (e.g. eNB, MME, S-GW).The entity used in the NR system may be identified by the name “NG” fordistinction from the LTE.

Referring to FIG. 1, the wireless communication system includes one ormore UE 11, a next-generation RAN (NG-RAN) and a 5th generation corenetwork (5GC). The NG-RAN consists of at least one NG-RAN node. TheNG-RAN node is an entity corresponding to the BS 20 shown in FIG. 1. TheNG-RAN node consists of at least one gNB 21 and/or at least one ng-eNB22. The gNB 21 provides NR user plane and control plane protocolterminations towards the UE 11. The ng-eNB 22 provides E-UTRA user planeand control plane protocol terminations towards the UE 11.

The 5GC includes an access and mobility management function (AMF), auser plane function (UPF) and a session management function (SMF). TheAMF hosts the functions, such as NAS security, idle state mobilityhandling, etc. The AMF is an entity including the functions of theconventional MME. The UPF hosts the functions, such as mobilityanchoring, protocol data unit (PDU) handling. The UPF an entityincluding the functions of the conventional S-GW. The SMF hosts thefunctions, such as UE IP address allocation, PDU session control.

The gNBs and ng-eNBs are interconnected with each other by means of theXn interface. The gNBs and ng-eNBs are also connected by means of the NGinterfaces to the 5GC, more specifically to the AMF by means of the NG-Cinterface and to the UPF by means of the NG-U interface.

A structure of a radio frame in NR is described. In LTE/LTE-A, one radioframe consists of 10 subframes, and one subframe consists of 2 slots. Alength of one subframe may be 1 ms, and a length of one slot may be 0.5ms. Time for transmitting one transport block by higher layer tophysical layer (generally over one subframe) is defined as atransmission time interval (TTI). A TTI may be the minimum unit ofscheduling.

Unlike LTE/LTE-A, NR supports various numerologies, and accordingly, thestructure of the radio frame may be varied. NR supports multiplesubcarrier spacings in frequency domain. Table 1 shows multiplenumerologies supported in NR. Each numerology may be identified by indexμ.

TABLE 1 Subcarrier Supported for Supported for μ spacing (kHz) Cyclicprefix data synchronization 0 15 Normal Yes Yes 1 30 Normal Yes Yes 2 60Normal, Yes No Extended 3 120 Normal Yes Yes 4 240 Normal No Yes

Referring to Table 1, a subcarrier spacing may be set to any one of 15,30, 60, 120, and 240 kHz, which is identified by index μ. However,subcarrier spacings shown in Table 1 are merely exemplary, and specificsubcarrier spacings may be changed. Therefore, each subcarrier spacing(e.g., μ=0, 1 . . . 4) may be represented as a first subcarrier spacing,a second subcarrier spacing . . . Nth subcarrier spacing.

Referring to Table 1, transmission of user data (e.g., physical uplinkshared channel (PUSCH), physical downlink shared channel (PDSCH)) maynot be supported depending on the subcarrier spacing. That is,transmission of user data may not be supported only in at least onespecific subcarrier spacing (e.g., 240 kHz).

In addition, referring to Table 1, a synchronization channel (e.g., aprimary synchronization signal (PSS), a secondary synchronization signal(SSS), a physical broadcast channel (PBCH)) may not be supporteddepending on the subcarrier spacing. That is, the synchronizationchannel may not be supported only in at least one specific subcarrierspacing (e.g., 60 kHz).

In NR, a number of slots and a number of symbols included in one radioframe/subframe may be different according to various numerologies, i.e.,various subcarrier spacings. Table 2 shows an example of a number ofOFDM symbols per slot, slots per radio frame, and slots per subframe fornormal cyclic prefix (CP).

TABLE 2 Number of symbols Number of slots Number of slots μ per slot perradio frame per subframe 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14160 16

Referring to Table 2, when a first numerology corresponding to μ=0 isapplied, one radio frame includes 10 subframes, one subframe correspondsto one slot, and one slot consists of 14 symbols. In the presentdisclosure, a symbol refers to a signal transmitted during a specifictime interval. For example, a symbol may refer to a signal generated byOFDM processing. That is, a symbol in the present disclosure may referto an OFDM/OFDMA symbol, or SC-FDMA symbol, etc. A CP may be locatedbetween each symbol. FIG. 3 shows an example of a frame structure towhich technical features of the present disclosure can be applied. InFIG. 3, a subcarrier spacing is 15 kHz, which corresponds to μ=0.

FIG. 2 illustrates an example of a frame structure to which thetechnical features of the present disclosure are applicable. In FIG. 2,a subcarrier spacing is 15 kHz which corresponds to μ=0.

FIG. 3 illustrates another example of a frame structure to which thetechnical features of the present disclosure are applicable. In FIG. 3,a subcarrier spacing is 30 kHz which corresponds to μ=1.

Meanwhile, a frequency division duplex (FDD) and/or a time divisionduplex (TDD) may be applied to a wireless communication system to whichembodiments of the present disclosure is applied. When TDD is applied,in LTE/LTE-A, UL subframes and DL subframes are allocated in units ofsubframes.

In NR, symbols in a slot may be classified as a DL symbol (denoted byD), a flexible symbol (denoted by X), and a UL symbol (denoted by U). Ina slot in a DL frame, the UE shall assume that DL transmissions onlyoccur in DL symbols or flexible symbols. In a slot in an UL frame, theUE shall only transmit in UL symbols or flexible symbols.

Table 3 shows an example of a slot format which is identified by acorresponding format index. The contents of the Table 3 may be commonlyapplied to a specific cell, or may be commonly applied to adjacentcells, or may be applied individually or differently to each UE.

TABLE 3 For- Symbol number in a slot mat 0 1 2 3 4 5 6 7 8 9 10 11 12 130 D D D D D D D D D D D D D D 1 U U U U U U U U U U U U U U 2 X X X X XX X X X X X X X X 3 D D D D D D D D D D D D D X . . .

For convenience of explanation, Table 3 shows only a part of the slotformat actually defined in NR. The specific allocation scheme may bechanged or added.

The UE may receive a slot format configuration via a higher layersignaling (i.e., radio resource control (RRC) signaling). Or, the UE mayreceive a slot format configuration via downlink control information(DCI) which is received on PDCCH. Or, the UE may receive a slot formatconfiguration via combination of higher layer signaling and DCI.

FIG. 4 shows an example of a resource grid to which technical featuresof the present disclosure can be applied.

An example shown in FIG. 4 is a time-frequency resource grid used in NR.An example shown in FIG. 4 may be applied to UL and/or DL. Referring toFIG. 4, multiple slots are included within one subframe on the timedomain. Specifically, when expressed according to the value of “μ”,“14·2μ” symbols may be expressed in the resource grid. Also, oneresource block (RB) may occupy 12 consecutive subcarriers. One RB may bereferred to as a physical resource block (PRB), and 12 resource elements(REs) may be included in each PRB. The number of allocatable RBs may bedetermined based on a minimum value and a maximum value. The number ofallocatable RBs may be configured individually according to thenumerology (“μ”). The number of allocatable RBs may be configured to thesame value for UL and DL, or may be configured to different values forUL and DL.

A cell search scheme in NR is described. The UE may perform cell searchin order to acquire time and/or frequency synchronization with a celland to acquire a cell identifier (ID). Synchronization channels such asPSS, SSS, and PBCH may be used for cell search.

<Self-Contained Subframe Structure>

For the purpose of minimizing latency in 5G NR, a structure in which acontrol channel and a data channel are TDMed, as illustrated in thefollowing figure, may be considered as a frame structure.

FIG. 5 schematically illustrates an example of a frame structure basedon a structure in which a data channel and a control channel aretime-division-multiplexed (TDMed).

Referring to FIG. 5, as an example of a frame structure, a singlesubframe (here, a subframe can be used interchangeably with atransmission time interval (TTI) can be represented on the basis of anindex of a resource block (RB) and an index of a symbol. Here, a singleTTI may include a region related to a downlink control channel, a regionrelated to an uplink control channel, and a downlink or uplink region.

For example, a TTI structure is described on the basis of FIG. 5. Ashaded region represents a downlink control region and a black regionrepresents an uplink control region. A blank region may be used fordownlink data transmission or uplink data transmission. This structureis characterized in that downlink (DL) transmission and uplink (UL)transmission are sequentially performed in a single subframe so that DLdata can be transmitted and UL ACK/NACK (Acknowledged/Not Acknowledged)can be received in the subframe. Consequently, a time taken toretransmit data when a data transmission error is generated is reduced,and thus final data delivery latency can be minimized.

In this data and control TDMed subframe structure, a time gap forswitching from a transmission mode to a reception mode or switching fromthe reception mode to the transmission mode between a base station and aUE is required. To this end, some OFDM symbols at a time when DLswitches to UL in a subframe structure is set to a guard period (GP).

<Analog Beamforming>

In mmW, wavelengths decrease and thus a plurality of antennas can beinstalled in the same area. That is, the wavelength in 30 GHz is 1 cmand a total of 100 antenna elements can be installed in a 2-dimensionalarrangement on a panel in 5×5 cm at intervals of 0.5λ (wavelength).Accordingly, coverage is increased or throughput is improved byincreasing a beamforming (BF) gain using a plurality of antenna elementsin mmW.

In this case, if a TXRU (transceiver unit) is provided for each antennaelement such that transmission power and phase can be controlled,beamforming independent for each frequency resource is possible.However, installation of TXRUs for all of 100 antenna elements isinefficient in terms of price. Accordingly, a method of mapping aplurality of antenna elements to one TXRU and controlling a beamdirection using an analog phase shifter is considered. Such an analogbeamforming method cannot provide frequency selective beaming becauseonly one beam direction can be generated in the entire band.

As an intermediate form of digital BF and analog BF, a hybrid BF havingB TXRUs fewer than Q antenna elements can be considered. In this case,the number of directions of beams that can be simultaneously transmittedis limited to B or less although it depends on a method of connecting BTXRUs and Q antenna elements.

<Analog Beamforming—2>

When multiple antennas are used in the NR system, hybrid beamformingthat is a combination of digital beamforming and analog beamforming isproposed. Here, analog beamforming (or RF beamforming) means anoperation of performing precoding (or combining) in an RF stage.

In the aforementioned hybrid beamforming, a baseband stage and an RFstage perform precoding (or combining), and thus it is possible toachieve performance close to digital beamforming while reducing thenumber of RF chains and the number of D/A (or A/D) converters.

For convenience, the aforementioned hybrid beamforming structure can berepresented by N transceiver units (TXRUs) and M physical antennas.Then, digital beamforming for L data layers to be transmitted by atransmitting stage can be represented by an N×L matrix, and N converteddigital signals are converted into analog signals through TXRU and thenanalog beamforming represented by an M×N matrix is applied thereto.

For convenience of understanding, the hybrid beamforming structure isschematically illustrated below in terms of TXRUs and physical antennas.

FIG. 6 schematically illustrates the hybrid beamforming structure interms of TXRUs and physical antennas.

According to the example of FIG. 6, the number of digital beams is L andthe number of analog beams is N. Furthermore, the NR system considerssupport of more efficient beamforming for UEs located in a specific areaby designing analog beamforming such that a base station can changeanalog beamforming in units of symbol.

Moreover, the NR system also considers introduction of a plurality ofantenna panels to which independent hybrid beamforming is applicablewhen N specific TXRUs and N RF antennas are defined as a single antennapanel in the example of FIG. 6.

When a base station uses a plurality of analog beams as described above,an analog beam suitable for signal reception may be different for UEs,and thus a beam sweeping operation through which a plurality of analogbeams to be applied by a base station are changed for respective symbolsin a specific subframe (SF) for at least a synchronization signal,system information, and paging such that all UEs can have receptionopportunities is considered.

Hereinafter, the beam sweeping operation for the synchronization signaland system information in a downlink transmission process will bedescribed in more detail with reference to the drawing.

FIG. 7 schematically illustrates an example of the beam sweepingoperation for the synchronization signal and system information in adownlink transmission process.

Referring to FIG. 7, physical resources (or a physical channel) throughwhich system information of the NR system is transmitted in abroadcasting manner may be referred to as a physical broadcast channel(xPBCH).

Analog beams belonging to different antenna panels can be simultaneouslytransmitted in one symbol, and a beam reference signal (BRS) that istransmitted with a single analog beam (corresponding to a specificantenna panel) applied thereto in order to measure a channel per analogbeam may be introduced.

The BRS can be defined for a plurality of antenna ports and each antennaport of the BRS can correspond to a single analog beam. Here, unlike theBRS, the synchronization signal or xPBCH can be transmitted with allanalog beams in an analog beam group applied thereto such that anarbitrary UE can correctly receive the same.

<Bandwidth Part (BWP)>

In the NR system, a maximum of 400 MHz can be supported per componentcarrier (CC). If a UE operating in such wideband CCs operates with RFfor all CCs turned on all the time, UE battery consumption may increase.Otherwise, when various use cases (e.g., eMBB, URLLC, mMTC, etc.)operating in a single wideband CC are considered, different numerologies(e.g., subcarrier spacings) may be supported for respective frequencybands in the corresponding CC. Otherwise, capability for a maximumbandwidth may be different for UEs.

In consideration of this, a base station can instruct a UE to operateonly in a part of a bandwidth instead of the entire bandwidth, and thecorresponding part of the bandwidth is defined as a bandwidth part(BWP). A BWP may be composed of resource blocks (RBs) consecutive in thefrequency domain and can correspond to one numerology (e.g., asubcarrier spacing, a CP length, and a slot/mini-slot duration).

Meanwhile, a base station can configure a plurality of BWPs even in oneCC configured for a UE. For example, a BWP that occupies a relativelysmall frequency domain may be configured in a PDCCH monitoring slot, anda PDSCH indicated by a PDCCH may be scheduled on a BWP greater than theBWP. Alternatively, when UEs are concentrated on a specific BWP, someUEs may be set to another BWP for load balancing.

Alternatively, some spectra at the center of a bandwidth may be excludedand BWPs on both sides of the bandwidth may be configured in the sameslot in consideration of frequency domain inter-cell interferencecancellation between neighbor cells.

That is, a base station may configure at least one DL/UL BWP for a UEassociated with a wideband CC and activate at least one of configuredDL/UL BWPs at a specific time (through L1 signaling or MAC CE or RRCsignaling), and switching to another configured DL/UL BWP may beindicated (through L1 signaling or MAC CE or RRC signaling) or switchingto a configured DL/UL BWP may be performed when a timer value expires onthe basis of a timer.

Here, an activated DL/UL BWP is defined as an active DL/UL BWP. However,when a UE is in an initial access procedure or in a situation before RRCconnection is set up, the UE may not receive a configuration withrespect to a DL/UL BWP. A DL/UL BWP assumed by the UE in such asituation is defined as an initial active DL/UL BWP.

Hereinafter, the present disclosure will be described.

As more communication devices require larger communication capacity,efficient utilization of a limited frequency band in future wirelesscommunication systems becomes more important.

In cellular communication systems such as LTE/NR systems, methods ofusing unlicensed bands such as 2.4 GHz mainly used in the legacy Wi-Fisystem or unlicensed bands such as 5 GHz and 60 GHz which newly attractattention for traffic offloading are under discussion. Since unlicensedbands basically assume wireless transmission and reception throughcontention between communication nodes, each communication node needs tocheck that other communication nodes do not transmit signals byperforming channel sensing before signal transmission.

This operation may be called listen before talk (LBT) or a channelaccess procedure (CAP) for convenience. In particular, an operation ofchecking whether other communication nodes transmit signals may becalled carrier sensing (CS), and when it is checked that othercommunication nodes do not transmit signals, it can be determined thatclear channel assessment has been checked.

eNBs or UEs of LTE/NR systems need to perform LBT for signaltransmission in an unlicensed band (referred to as a U-band forconvenience), and other communication nodes also need to perform LBTwhen eNBs or UEs of the LTE/NR systems transmit signals such thatinterference does not occur.

For example, a CCA threshold is defined as −62 dBm for non-WiFi signalsand −82 dBm for WiFi signals in WiFi standard (801.11ac), which may meanthat an STA or an AP does not transmit a signal such that interferencedoes not occur when a signal other than WiFi signals is received withpower of −62 dBm or more.

In LTE eLAA, two types of channel access procedure for UL datatransmission are defined.

LBT type 1 is a mechanism based on random back-off similar to a channelaccess procedure used for DL data transmission, and LBT type 2 regards achannel as idle when an energy measured through short channelmeasurement (CCA) of at least 25 μs immediately before UL transmissionstarts is lower than a threshold and can start UL transmission.

ETSI EN 301 893 describes that a UE (or a responding device) can performUL transmission without CCA if the UE can start UL transmission within16 μs after reception of a UL grant of an eNB (or an initiating device),and a procedure of performing UL transmission without LBT because a gapbetween DL and UL is less than 16 μs will be referred to as LBT type 3or no LBT in the present disclosure.

Channel access schemes with respect to NR based access for an unlicensedspectrum may be classified into categories below. Hereinafter, LBT typesand categories may be described in a combined manner for convenience ofdescription.

-   -   Category 1 (hereinafter, CAT 1): Immediate transmission after a        short switching gap. Here, category 1 may refer to LBT type 3.    -   Category 2 (hereinafter, CAT 2): LBT without random back-off.        Here, category 2 may refer to LBT type 2.    -   Category 3 (hereinafter, CAT 3): LBT with random back-off with a        contention window of fixed size.    -   Category 4 (hereinafter, CAT 4): LBT with random back-off with a        contention window of variable size. Here, category 4 may refer        to LBT type 1.

Transmission of uplink data such as a PUSCH is indicated by DCI (i.e., aUL grant) transmitted through a PDCCH, and this DCI includes an LBT typeto be used by a UE when the UE performs a channel access procedure andinformation about a PUSCH starting position.

Specifically, a 1-bit field in the DCI indicates whether an LBT type tobe used for a channel access procedure is type 1 or type 2, and another2-bit field indicates one of four available PUSCH starting positions{symbol 0, symbol 0+25 μs, symbol 0+25 μs+timing advance (TA), symbol1}.

In the present disclosure, a position of a PUSCH transmission startingsymbol may be flexibly indicated as one of symbols constituting a slotas in NR, and a new UL scheduling indication method when LBT type 3 isintroduced as an additional channel access procedure in addition to LBTtype 1 and LBT type 2 in an NR unlicensed band (NR-U) and an LBTexecution method according to UL slot spacing during multiple UL slotscheduling are proposed. In addition, a method of setting a margin inconsideration of a processing time of a UE depending on an LBT type isalso proposed.

Hereinafter, a method of setting a margin in a processing time dependingon an LBT type, a multiple UL slot scheduling method, and a method ofindicating an LBT type and a PUSCH starting position during ULscheduling will be described with reference to the drawings.

Here, respective items do not necessarily independently operate. Thatis, technical features described in the specification may be combinedunless they are contrary to each other. Furthermore, technical featuresdescribed in the specification may separately operate.

FIG. 8 is a flowchart of a method for performing an operation dependingon an LBT type in an unlicensed band according to an embodiment of thepresent disclosure.

Referring to FIG. 8, a UE may acquire information about the LBT type andinformation about a physical uplink shared channel (PUSCH) startingposition from an eNB through an uplink (UL) grant (S810). Here, theinformation about the PUSCH starting position may be informationindicating any one position among a plurality of PUSCH starting positioncandidates. Here, a specific example in which the UE acquires theinformation about the LBT type and the information about the PUSCHstarting position will be described later.

The UE may implement at least one advanced driver assistance system(ADAS) function on the basis of a signal for controlling movement of adevice, receive a user input and switch a device driving mode from anautonomous traveling mode to a manual driving mode or switch the devicedriving mode from the manual driving mode to the autonomous drivingmode, and/or autonomously travel on the basis of external object tinformation, and the external object information may include at leastone of information about presence or absence of an object, positioninformation of the object, information on a distance between the deviceand the object, and information on a relative speed of the device withrespect to the object.

Subsequently, the UE may perform an operation depending on the LBT typeon the basis of the acquired LBT type (S820). Here, a specific examplein which the UE performs the operation depending on the LBT type will bedescribed later for convenience of description.

After execution of the operation depending on the LBT type, the UE maytransmit a PUSCH on the basis of the information about the PUSCHstarting position (S830). A specific example in which the UE transmits aPUSCH on the basis of the information about the PUSCH starting positionafter execution of the operation depending on the LBT type will bedescribed later.

As will be described later, for example, the information about the LBTtype indicates one of LBT type 1, LBT type 2, and LBT type 3, asdescribed above, and the UE may perform LBT based on random back-off inLBT type 1, may perform LBT without random back-off in LBT type 2, andmay not perform LBT in LBT type 3. More specific examples with respectto this will be described later for convenience of description.

As will be described later, for example, first uplink and second uplinkmay be scheduled for the UE and the UE may perform the LBT on the basisof a gap between the first uplink and the second uplink. More specificexamples with respect to this will be described later for convenience ofdescription.

As will be described later, for example, downlink and uplink may bealternatively scheduled within a channel occupancy time (COT) acquiredby the UE. Here, first downlink may be scheduled for the UE afterscheduling of the first uplink and the second uplink may be scheduledfor the UE after scheduling of the first downlink within the COT, andthe LBT type may be determined differently on the basis of whether firstdownlink transmission has been performed. More specific examples withrespect to this will be described later for convenience of description.

As will be described later, for example, when transmission of aplurality of links is scheduled within the channel occupancy time (COT),on the basis of the size of a transmission bandwidth of a previous link,a transmission bandwidth of the following link may be limited. Here, thelinks may be uplink or downlink, the first downlink, the first uplink,and the second downlink may be sequentially scheduled in the time domainwithin the COT, and the transmission bandwidth of the first uplink maybe determined on the basis of the size of the transmission bandwidth ofthe first downlink. More specific examples with respect to this will bedescribed later for convenience of description.

As will be described later, for example, the UL grant may include startand length indicator value (SLIV) information, the SLIV information mayindicate an index of a starting symbol and the number of symbolsconstituting the PUSCH, the symbol indicated by the SLIV information maybe symbol #K, and K may be a positive integer. Here, the plurality ofPUSCH starting position candidates may be at least one of a set of firstPUSCH starting position candidates and a set of second PUSCH startingpositions, the first PUSCH starting position candidate set may includesymbol #(K-N)+16 μs, symbol #(K-N)+16 μs+TA, symbol #(K-N)+25 μs, symbol#(K-N)+25 μs+TA, and symbol #K, the second PUSCH starting positioncandidate set may include symbol #K, symbol #K+16 μs, symbol #K+16μs+TA, symbol #K+25 μs, and symbol #K+25 μs+TA, and N may be a valuebased on a subcarrier spacing. Here, the UE may determine a transportblock size (TBS) of the PUSCH on the basis of association between thestarting symbol index indicated by the SLIV information and a referencesymbol index when the PUSCH starting position is indicated. Here, thereference symbol index may be symbol #(K-N) when the PUSCH startingposition is between symbol #(K-N) and symbol #K, and the referencesymbol index may be symbol #K when the PUSCH starting position isbetween symbol #K and symbol #(K+N). More specific examples with respectto this will be described later for convenience of description.

Hereinafter, the example of FIG. 8 will be described in more detail.

<Method of Setting Margin in Processing Time Depending on LBT Type>

1. First Method:

A method of setting a margin in a processing time of a UE depending onan LBT type when an eNB instructs the UE to transmit a PUCCH or a PUSCHmay be provided.

The UE instructed by the eNB to transmit a PUCCH or a PUSCH may need aprocessing time for UL transmission after the corresponding ULscheduling.

In the case of a PUCCH, for example, the UE needs to generate HARQ-ACKthat is a decoding result for received DL data and transmit the PUCCH,and a time required for this may be regarded as a processing time.

However, in an unlicensed band, the UE can start transmission only whenthe UE has successfully performed BLT before UL transmission accordingto the size of a gap between DL and UL.

Since LBT is not performed when a gap between DL and UL transmissionsuch as PUCCH or PUSCH transmission is 16 us or less, the eNB canperform UL scheduling on the basis of corresponding informationdepending on processing capability of the UE reported by the UE when theUE initially accesses the eNB.

However, when the gap exceeds 16 μs, LBT must be performed before ULtransmission and thus a time taken to perform LBT may be additionallyrequired in addition to processing time capability of the UE.

Accordingly, when the eNB indicates UL transmission such as PUCCH orPUSCH transmission with a gap of 16 μs or more (or when an LBT typeother than LBT type 3 is indicated for UL transmission), a marginrequired to perform LBT may be added to the processing time capabilityof the UE.

A margin value may be set to 25 μs or max (one symbol duration, 25 μs)when an LBT type is one-shot LBT.

For example, a minimum value of a gap that can be accomplished by the UEfor a gap between a time at which the last symbol of a PDSCH is receivedand a time at which the first symbol of a PUCCH is transmitted may bedefined as a processing time capability of the UE for PUCCHtransmission, and if the corresponding value is N1 symbol, PUCCHtransmission can be indicated on the assumption that N1 symbol spacingis a processing time capability of the UE for PUCCH transmission as inthe conventional method with respect to a PUCCH for which LBT type 3 isindicated.

If the corresponding value is N1 symbol, PUCCH transmission can beindicated on the assumption that N1 symbol+25 μs (or max(one symbolduration, 25 μs)) spacing is a processing time capability of the UE forPUCCH transmission with respect to a PUCCH for which LBT type 2 isindicated.

When an LBT type is LBT based on random back-off, the margin value maybe determined in consideration of an LBT execution time. Typically, themargin value may be set differently for priority classes of data to betransmitted.

TABLE 4 Channel Access Priority allowed CW_(p) Class (p) m_(p)CW_(min, p) CW_(max, p) T_(ulmcot, p) sizes 1 2 3 7 2 ms {3, 7}  2 2 715 3 ms {7, 15} 3 3 15 1023 6 ms or {15, 31, 63, 127, 10 ms 255, 511,1023} 4 7 15 1023 6 ms or {15, 31, 63, 127, 10 ms 255, 511, 1023}

That is, a margin value suitable for a priority class of data to betransmitted by the UE is required because a time required to perform LBTis different for priority classes defined in Table 4.

Here, a larger margin value can be set for a larger priority classvalue. For example, when data of a PUSCH to be transmitted has apriority class of 1 (i.e., p=1), a minimum of 16+2×9 μs may be needed.Further, a margin value may be set in consideration of allowed CW valuesin the corresponding priority class.

The LBT operation may be performed in parallel with an operation ofprocessing a PUCCH and/or a PUSCH. In this case, a processing timemargin in consideration of the LBT operation may not be considered.Accordingly, the corresponding method can be applied according towhether the LBT operation and the operation of processing a PUCCH and/ora PUSCH can be performed in parallel (e.g., UE capability), that is,only when the parallel operation cannot be performed.

Meanwhile, the present disclosure is not limited to direct communicationbetween UEs and may be used for uplink or downlink. Here, eNBs or relaynodes can use the above-proposed method.

The above-described examples of the proposed method may be included asone of methods implemented by the present disclosure and thus can beregarded as proposed methods. In addition, although the above-describedproposed methods may be independently implemented, some of the proposedmethods may be combined (or aggregated). A rule may be defined such thatinformation about whether the proposed methods are applied (orinformation about rules of the proposed methods) is signaled by an eNBto a UE or signaled by a transmitting UE to a receiving UE through apredefined signal (e.g., a physical layer signal or a higher layersignal).

<Multiple UL Slot Scheduling Method>

Meanwhile, the eNB may schedule multiple UL slots for the UE and the UEmay perform LBT on the basis of a spacing between the multiple UL slots.

Hereinafter, specific examples will be described.

1. First Method

An LBT execution method in response to a spacing between UL slots whenan eNB schedules multiple UL slots for a UE may be provided.

FIG. 9 schematically illustrates an example of UL #1 and UL #2 scheduledas consecutive UL bursts having a time-domain gap within a COT.

The first UL scheduling UL #1 is indicated as one-shot LBT (i.e., LBTtype 2) and the second UL scheduling UL #2 is indicated as no LBT (i.e.,LBT type 3) in a UL grant, and thus the following methods may beprovided when UL #1 and UL #2 are consecutive UL bursts having atime-domain gap therebetween as illustrated in FIG. 9.

(1) When UL #1 and UL #2 are Scheduled for the Same UE,

When UL #1 and UL #2 are scheduled for the same UE, whether the UE hassuccessfully performed LBT of UL #1 can be ascertained. Accordingly, thefollowing methods may be provided.

1) A method of automatically dropping UL #2 when LBT of UL #1 has failedmay be provided.

2) A method of attempting LBT type 2 for UL #2 even when LBT type 3 isindicated for UL #2 when LBT of UL #1 has failed may be provided.

3) A method of transmitting UL #2 without LBT when LBT of UL #1 hasfailed may be provided.

4) A method of performing LBT type 2 for UL #2 if LBT of UL #1 hasfailed when LBT type 2 is indicated for UL #1 may be provided.

5) A method of applying LBT type 3 only to UL scheduling immediatelyafter DL may be provided.

6) A method of indicating an LBT type as follows through DCI forscheduling UL #n (n=1 or 2) transmission may be provided.

A. Unconditional LBT type 3

B. Conditional LBT type 3

Here, when unconditional LBT type 3 of A is indicated, the UE mayunconditionally perform UL #n transmission as indicated. Whenconditional LBT type 3 of B is indicated, methods of performing UL #ntransmission may be provided as follows.

-   -   When transmission of another UL #k (e.g., k may be 1 when n=2)        is indicated/performed within 16 μs from a time at which        transmission of UL #n starts (or when DL transmission or a part        thereof, e.g., a DM-RS and a CSI-RS, is received within 16 μs        from the time at which transmission of UL #n starts), the UE can        perform UL #n transmission on the basis of LBT type 3.    -   When transmission of another UL #k (e.g., k may be 1 when n=2)        is not indicated/performed within 16 μs from a time at which        transmission of UL #n starts (or when DL transmission or a part        thereof, e.g., a DM-RS and a CSI-RS, is not received within 16        μs from the time at which transmission of UL #n starts), the UE        can perform UL #n transmission on the basis of an LBT type        defined or set in advance (e.g., LBT type 1).

7) A method of indicating an LBT type as follows through DCI forscheduling UL #n (n=1 or 2) transmission may be provided.

A. Unconditional LBT type 2

B. Conditional LBT type 2

Here, when unconditional LBT type 2 of A is indicated, the UE mayunconditionally perform UL #n transmission on the basis of LBT type 3 asindicated. When conditional LBT type 2 of B is indicated, methods ofperforming UL #n transmission may be provided as follows.

-   -   When transmission of another UL #k (e.g., k may be 1 when n=2)        is indicated/performed within T (e.g., 25) μs from a time at        which transmission of UL #n starts (or when DL transmission or a        part thereof, e.g., a DM-RS and a CSI-RS, is received within T        (e.g., 25)μs from the time at which transmission of UL #n        starts), the UE can perform UL #n transmission on the basis of        LBT type 2.    -   When transmission of another UL #k (e.g., k may be 1 when n=2)        is not indicated/performed within T (e.g., 25) μs from a time at        which transmission of UL #n starts (or when DL transmission or a        part thereof, e.g., a DM-RS and a CSI-RS, is received within T        (e.g., 25) μs from the time at which transmission of UL #n        starts), the UE can perform UL #n transmission on the basis of        an LBT type defined or set in advance (e.g., LBT type 1).

(2) When UL #1 and UL #2 are Scheduled for Different UEs,

A method by which this scheduling is not allowed may be provided becausea UE for which UL #2 is scheduled cannot be aware of whether a UE forwhich UL #1 is scheduled successfully performs LBT or fails to performLBT.

2) A method of always indicating the same LBT type when UL #1 and UL #2are scheduled for different UEs. That is, a method of indicating andscheduling LBT type 2 for UL #2 when LBT type 2 is indicated for UL #1and indicating and scheduling LBT type 3 for UL #2 when LBT type 3 isindicated for UL #1 may be provided.

However, the methods of (2) are also applicable to a case in which noLBT is indicated for UL #1 and one-shot LBT is indicated for UL #2 whenUL #1 and UL #2 are scheduled for different UEs.

FIG. 10 schematically illustrates an example of UL #1 and UL #2scheduled as consecutive UL bursts having a time-domain gap within a COTwith different grants.

This illustrates a method by which indication of LBT type 3 isapplicable only to UL #1 scheduling and LBT type 2 is applied to UL #2scheduling when UL #1 and UL #2 are scheduled for different UEs in (2).

Here, UL #1 and UL #2 may be a PUCCH or a PUSCH. UL #1 and UL #2 may beUL transmission scheduled for the same UE or UL transmission scheduledfor different UEs. Although a case of different UEs is described forconvenience, the same method can be applied to a case of the same UE.

For example, when UE A misses or mis-detects DCI for scheduling UL #1and thus cannot perform UL transmission, UE B for which UL #2 isscheduled cannot ascertain whether UE A misses or mis-detects UL #1scheduling and thus cannot perform UL #2 transmission without LBTbecause a gap between DL and UL exceeds 16 μs when there is no UL #1transmission. If UE B transmits UL #2 through LBT type 3, collision withother UEs may occur.

Accordingly, LBT type 3 is a method applied/indicated for UL schedulingimmediately following DL (specifically, when a gap between a last DLtransmission time and a scheduled UL or UL transmission starting time is16 μs or less).

In other words, with respect to UL transmissions (e.g., PUSCH or PUCCH)sharing a COT acquired by the eNB, a scheduling restriction that LBTtype 3 cannot be indicated for following UL transmission when the ULtransmissions are TDMed and a gap is present between UL transmissionsmay be applied.

LBT type 3 is an LBT method applicable when a gap between UL #1 and UL#2 of FIG. 9 is 16 μs or less, and when the gap exceeds 16 μs and isequal to or less than 25 μs, LBT type 2 may be applied to transmit UL#2.

In addition, UL #1 and UL #2 TDMed as described above may be scheduledwith different grants, as illustrated in FIG. 10, or UL #1 and UL #2 maybe scheduled with a single UL grant, as illustrated in FIG. 9. If UL #1and UL #2 are scheduled with a single UL grant, as illustrated in FIG.9, LBT type 3 may also be applied to UL #2 because a situation in whichscheduling DCI is missed or mis-detected does not occur even when UL #1and UL #2 are scheduled for different UEs.

2. Second Method

A method through which multiple DL transmissions and UL transmissionsare scheduled during multiple DL/UL switching within a COT acquired byan eNB (in a case where LBT type 3 is indicated for all UL transmissionsbecause a gap between transmissions is 16 μs or less or a case in whichLBT type 2 is indicated because the gap is equal to or greater than 16μs and equal to or less than 25 μs), and an LBT type performedimmediately before DL transmission is varied according to whether a(scheduled) UE performs UL transmission before the DL transmission ofthe eNB may be provided.

(1) When the eNB detects that UL transmission scheduled for the UE hasbeen successfully performed (or the UL transmission or a part thereof,e.g., DM-RS, SRS and PRACH, has been successfully received),

A. A method through which the eNB performs DL transmission through LBTtype 3 when a gap between the scheduled UL transmission and following DLtransmission is 16 μs or less may be provided.

B. A method through which the eNB performs DL transmission through LBTtype 2 when a gap between the scheduled UL transmission and following DLtransmission exceeds 16 μs and is equal to or less than 25 μs.

(2) When the eNB detects that UL transmission scheduled for the UE hasnot been performed (or the UL transmission or a part thereof, e.g.,DM-RS, SRS and PRACH, has not been successfully received),

A. A method of performing LBT type 1 or 2 and performing DL transmissionbecause a gap between immediately previous DL or immediatelysuccessfully received UL transmission is 16 μs or more in a case where aUE misses or mis-detects UL scheduling so that UL transmission is notperformed. For example, LBT type 2 may be performed if the gap is 25 μsor less and LBT type 1 may be performed if the gap exceeds 25 μs.

Here, the aforementioned gap between transmission means a gap betweentransmissions when DL transmission switches to UL transmission or ULtransmission switches to DL transmission.

In addition, the eNB may detect whether UL transmission is performedthrough detection of a DMRS sequence in a PUSCH or energy detection. Inconsideration of a time taken for the eNB to sufficiently detect whetherUL transmission is performed and prepare the next DL transmission, ULtransmission of the UE may be performed using interlace in which a PUSCHBW (or the number of RBs) is X or more, and UL transmission including aDMRS may need to be indicated/configured before a specific Y symbol froman ending slot boundary in the time domain (or immediately before thenext DL transmission) (in order for the eNB to secure a gap between ULand DL).

FIG. 11 schematically illustrates an example of multiple DL or ULtransmissions during multiple DL/UL switching within a COT acquired by agNB.

For example, consider a case in which all gaps between transmissionswhen multiple DL and UL transmissions are performed during multipleDL/UL switching within a COT acquired by a gNB through LBT type 1, thatis, gaps when DL switches to UL or UL switches to DL, are 16 μs or lessso that all transmissions are performed through LBT type 3.

If a UE misses or mis-detects UL #1 scheduling and UL grant, the gNBcannot perform DL #2 transmission through LBT type 3 because UL #1transmission is not detected. In this case, the gNB can perform LBT type1 or LBT type 2 and then transmit DL #2 when LBT type 1 or LBT type 2has been successfully performed.

3. Third Method

A method through which a PRACH and a specific UL signal/channel arecombined and transmission thereof is configured/indicated in UL #1 andan eNB checks presence or absence of UL #2 transmission and transmit DL#2 when a UL #1 slot is a RACH transmission slot in a DL #1-UL #1-DL #2structure and all gaps between transmissions are 16 μs or less so thatno LBT is scheduled for DL #2 after UL #1 transmission or the gaps areequal to or greater than 16 μs and equal to or less than 25 μs so thatLBT type 2 is scheduled

FIG. 12 schematically illustrates an example of transmission duringmultiple DL/UL switching in a DL #1-UL #1-DL #2 structure within a COTacquired by a gNB.

As illustrated in FIG. 12, if all transmissions are performed asscheduled when LBT type 3 is scheduled for UL #1 and DL #2 having a timegap of 16 μs or less within a gNB-initiated COT in which transmission ofa UL grant and DL #1 starts, UL #1 and DL #2 can be consecutivelytransmitted through LBT type 3 because the gap therebetween is less than16 μs.

However, when a UE misses or mis-detects UL #1 scheduling, UL #1 is nottransmitted and thus the gap between DL #1 and DL #2 increases to begreater than 16 μs. Accordingly, to safely transmit DL #2 through LBTtype 3 after UL #1 transmission, the gNB needs to transmit DL #2 inorder to determine whether UL #1 has been successfully transmitted.

However, in a case where UL #1 is a RACH transmission slot, a processingtime may be insufficient when the gNB transmits DL #2 without LBTimmediately after detection of a PRACH sequence.

Accordingly, specific UL signals/channels may be combined into a packageand transmission of the packet may be configured/indicated immediatelyafter a PRACH such that the gNB can detect a sequence part in advance toascertain presence or absence of UL transmission.

For example, transmission of MsgA (PRACH sequence+Msg3 PUSCH) for 2-stepRACH is configured/indicated in a short PUCCH conveying an SR or a CSIreport, or an SRS, more typically, the corresponding RACH transmissionslot such that the gNB can easily ascertain presence or absence of ULtransmission (in order to allow the gNB to successfully performdetection).

Furthermore, to allow the gNB to obtain information about a transport BWwith low complexity, different DM-RS sequence resources may beconfigured in advance for transport BWs such that the gNB can ascertaina transport BW only through DM-RS detection.

Here, the gap between transmissions means a gap between transmissionswhen DL transmission switches to UL transmission or when UL transmissionswitches to DL transmission.

In addition, the gNB can detect whether UL transmission is performedthrough sequence detection or energy detection. In consideration of atime taken for the gNB to sufficiently detect whether UL transmission isperformed and prepare the next DL transmission, UL transmission of theUE may be performed using interlace in which a BW (or the number of RBs)is X or more, and UL transmission including a DMRS may need to beindicated/configured before a specific Y symbol from an ending slotboundary in the time domain (or immediately before the next DLtransmission) (in order for the eNB to secure a gap between UL and DL).

4. Fourth Method

A method through which multiple DL transmissions and UL transmissionsare scheduled during multiple DL/UL switching within a COT acquired by aUE, and an LBT type performed immediately before UL transmission isvaried according to whether (scheduled) DL transmission of an eNB isperformed before the UL transmission of the UE (in a case where a gapbetween transmissions is 16 μs or less so that LBT type 3 is scheduledfor all DL transmissions or a case where the gap is equal to or greaterthan 16 μs and equal to or less than 25 μs so that LBT type 2 isscheduled)

In other words, downlink and uplink can be scheduled while switchingwithin the channel occupancy time (COT) acquired by the UE. Here, basedon whether downlink transmission of the gNB, scheduled before uplinktransmission of the UE, has been performed, the LBT type performedimmediately before the uplink transmission may be differentlydetermined. Hereinafter, this will be described with reference to thedrawings for convenience of description.

FIG. 13 schematically illustrates an example of transmission duringmultiple DL/UL switching in a UL #1-DL #1-UL #2 structure within a COTacquired by a UE.

(1) When the UE detects that DL transmission scheduled before ULtransmission thereof has been successfully performed (or the DLtransmission or a part thereof, e.g., a PDCCH DM-RS, a PDSCH DM-RS, aCSI-RS, and SS/PBCH block, is successfully received)

A. A method through which the UE performs UL transmission through LBTtype 3 when a gap between scheduled DL transmission and following ULtransmission is 16 μs or less

B. A method through which the UE performs UL transmission through LBTtype 2 when a gap between scheduled DL transmission and following ULtransmission exceeds 16 μs and equal to or less than 25 μs

(2) When the UE detects that DL transmission scheduled before ULtransmission thereof has not been performed (or the DL transmission or apart thereof, e.g., a PDCCH DM-RS, a PDSCH DM-RS, a CSI-RS, and SS/PBCHblock, is not successfully received)

A. A method through which a gNB performs LBT type 1 or 2 and performs DLtransmission because a gap between immediately previous ULs orimmediately successfully received DL transmissions is 16 μs or more whenthe gNB cannot receive information about COT sharing from the UE. Forexample, LBT type 2 can be performed if the gap is 25 μs or less and LBTtype 1 can be performed if the gap exceeds 25 μs.

Here, the gap between transmissions means a gap between transmissionswhen DL transmission switches to UL transmission or UL transmissionswitches to DL transmission. In addition, the UE can detect whether DLtransmission is performed through detection of a DMRS sequence in aPUCCH or a PDSCH or energy detection. In consideration of a time takenfor the UE to sufficiently detect whether DL transmission is performedand prepare the next UL transmission, DL transmission of the gNB may beperformed using interlace in which a PDSCH BW (or the number of RBs) isX or more, and DL transmission including a DMRS may need to beindicated/configured before a specific Y symbol from an ending slotboundary in the time domain (or immediately before the next ULtransmission).

5. Fifth Method

When a BW of a DL/UL BWP configured for a gNB and a UE is 20 MHz ormore, and a COT acquired by the gNB (or UE) through LBT is shared withthe UE (or gNB) and multiple DL/UL transmissions are scheduled withinthe COT of the gNB (or UE), a method of limiting a size of a transportBW of following DL or UL within the COT in response to a size of atransport BW of previous DL or UL or not allowing DL transmissionfollowing corresponding UL transmission (allowing COT sharing only oncewhen a BW of following transmission is less than a BW of COT initiatedtransmission when the COT is shared) may be provided.

In other words, when multiple link transmissions are scheduled betweenthe UE and the gNB, a transport bandwidth of a following link may belimited on the basis of a size of a transport bandwidth of a previouslink. Here, the links may be uplink or downlink, and the uplink and thedownlink may be alternately scheduled between the UE and the gNB.

For example, the gNB (or UE) may share a COT remaining after DL (or UL)transmission in a COT acquired through Cat-4 LBT with the UE (or gNB).Here, a transport BW of a DL/UL signal and channel to be transmitted bythe UE (or gNB) sharing the COT may be equal to or less than a transportBW of an immediately previously transmitted DL/UL signal and channel.

FIG. 14 schematically illustrates an example of transmission duringmultiple DL/UL switching in a DL #1-UL #1-DL #2 structure within a COTof a gNB.

For example, the gNB may successfully performs LBT in both of two 20 MHzLBT sub-bands in a BWP having a BW of 40 MHz and share a COT remainingafter DL #1 transmission through 40 MHz with a UE, as illustrated inFIG. 14.

When a gap between DL #1 and UL #1 is greater than 16 μs and less than25 μs, the UE may attempt LBT type 2 in the two LBT sub-bands before UL#1 transmission and perform transmission only through a sub-band inwhich LBT type 2 has been successfully performed.

This is because, when transmission is performed through 20 MHz in UL #11410, another gNB (or another UE) determines that other communicationnodes do not transmit signals through LBT in area A 1420 of FIG. 14 andthen the other UE can perform DL (or UL) transmission in area B 1440.

Accordingly, when the UE successfully performs LBT only in the upper 20MHz LBT sub-band and performs UL transmission in a transport BW of 20MHz, as illustrated in the figure, DL #2 following the UL transmissioncan be transmitted only in a BW of 20 MHz or less because the transportBW of immediately previously transmitted UL #1 is 20 MHz.

Accordingly, the gNB needs to check presence or absence of UL #1transmission performed immediately before DL #2 transmission andascertain a transport BW before DL #2 transmission.

The gNB needs to detect a DM-RS sequence of UL #1 as in theabove-described second method or third method or transmit informationabout the transport BW to check presence or absence of UL #1 and thetransport BW and then transmit DL #2. In the case of UL #1-DL #1-UL #2,the UE may check presence or absence of DL #1 transmission and atransport BW through detection of a DMRS in a PDCCH or a PDSCH before UL#2 transmission and then transmit UL #2 as in the fourth method.

To allow the gNB or the UE sharing a COT to rapidly obtain informationabout a transport BW with low complexity, different DM-RS sequenceresources may be configured in advance for transport BWs such that thegNB or the UE can ascertain a transport BW only through DM-RS detection.

<Method of Indicating LBT Type and PUSCH Starting Position During ULScheduling>

1. First Method

When LBT type 1 is referred to as back-off based LBT, LBT type 2 isreferred to as one-shot LBT, and LBT type 3 is referred to as no LBT, amethod of indicating an LBT type and a PUSCH starting position inconsideration of multiple subcarrier spacings (SCS) may be provided.

An eNB may indicate, to a UE, a time-domain resource of a PUSCH, thatis, a starting symbol position and the number of symbols constitutingthe PUSCH through a start and length indicator value (SLIV) in a ULgrant.

For example, the UL grant (e.g., DCI) may include SLIV information, andthe SLIV information may indicate a starting symbol index and the numberof symbols constituting the PUSCH. Here, the symbol indicated by theSLIV information may be symbol #K and K may be a positive integer.

In addition to the SLIV, the eNB may indicate, to the UE, a PUSCHstarting position in consideration of an LBT type to be used in achannel access procedure and an LBT execution time.

When the symbol indicated through SLIV is #K, available PUSCH startingposition candidates may be defined as {symbol #(K-N)+16 μs, symbol#(K-N)+16 μs+TA, symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA, symbol #K}or {symbol #K, symbol #K+16 μs, symbol #K+16 μs+TA, symbol #K+25 μs,symbol #K+25 μs+TA}. Here, {symbol #(K-N)+16 μs+TA} or {symbol #K+16μs+TA} may be replaced with {symbol #(K−1)+max(16 μs, TA)} or {symbol#K+max(16 μs, TA)}.

In other words, the PUSCH starting position candidates may be symbol#(K-N)+16 μs, symbol #(K-N)+16 μs+TA, symbol #(K-N)+25 μs, symbol#(K-N)+25 μs+TA, or symbol #K, or the PUSCH starting position candidatesmay be symbol #K, symbol #K+16 μs, symbol #K+16 μs+TA, symbol #K+25 μs,or symbol #K+25 μs+TA and N may be a value based on s subcarrierspacing. Here, information about the PUSCH starting position canindicate any one of the PUSCH starting position candidates.

When DL transmission is performed until a symbol immediately before aPUSCH transmission starting symbol and then TA is present in the firstsymbol of the next slot (e.g., when UL transmission starts immediatelyafter (16 μs-TA) from DL reception), {symbol #(K−1)+16 μs+TA} or {symbol#K+16 μs+TA} may be excluded from the PUSCH starting positioncandidates.

Meanwhile, one of four PUSCH starting candidates may be indicated to theUE using 2 bits in a UL grant.

Here, TA may represent timing advance. N may be predefined as a specificvalue (e.g., N=1), additionally set/indicated through RRC signaling (orthrough DCI or a combination of RRC and DCI), or scalably set by an eNBfor a UE as different values according to numerologies.

For example, N may be 1 in the case of a subcarrier spacing (SCS) of 15kHz and 2 in the case of an SCS of 30 kHz.

Alternatively, when the SCS is greater than 15 kHz, a starting positionpassing the next symbol boundary of symbol #K from among {symbol #K+16μs, symbol #K+25 μs, symbol #K+25 μs+TA} and a starting position passingthe previous symbol boundary of symbol #(K−1) from among {symbol#(K−1)+16 μs, symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA, symbol #K}may be excluded.

Meanwhile, although LBT type 1 or 2 is indicated in eLAA so that an LBTtype can be indicated using 1 bit, a method of increasing an LBT typeindication field in the UL grant to 2 bits and indicating one of threeLBT types may also be provided in order to indicate LBT types includingLBT type 3 to a UE. In this case, a PUSCH starting position may bedifferently interpreted as follows depending on indicated LBT types.

(1) A method of indicating a PUSCH starting position as one of {symbol#(K-N)+25 μs, symbol #(K-N)+25 μs+TA, symbol #K} or {symbol #K, symbol#K+25 μs, symbol #K+25 μs+TA} when LBT type 1 or 2 is indicated

(2) A method of indicating a PUSCH starting position as one of {symbol#(K-N)+16 μs, symbol #(K-N)+16 μs+TA, symbol #K} or {symbol #K, symbol#K+16 μs, symbol #K+16 μs+TA} when LBT type 3 is indicated

As another method, a method of indicating LBT type 1 or 2 using a 1-bitLBT type indication field by applying joint coding in order to reducethe size of the LBT type indication field and parsing a case in which aPUSCH starting position is {symbol #(K-N)+16 μs}, {symbol #K+16 μs},{symbol #(K-N)+16 μs+TA}, or {symbol #K+16 μs+TA} as indication of LBTtype 3 is possible.

Furthermore, the following proposed method may also be provided.

2. Second Method

A method of determining a transport block size (TBS) of a PUSCHaccording to association between a starting symbol index indicated by astart and length indicator value (SLIV) in a UL grant (PUSCH schedulingDCI) and a reference symbol index when a PUSCH starting positionconsidering an LBT type and a subcarrier spacing may be provided.

That is, the UE can determine the TBS of the PUSCH on the basis ofassociation between the starting symbol index indicated by the SLIVinformation and the reference symbol index when the PUSCH startingposition is indicated.

Here, the reference symbol index may be symbol #(K-N) when the PUSCHstarting position is between symbol #(K-N) and symbol #K and symbol #Kwhen the PUSCH starting position is between symbol #K and symbol #(K+N).

Here, a reference symbol is determined as symbol #(K-N) when the PUSCHstarting position is disposed between symbol #(K-N) and symbol #K and assymbol #K when the PUSCH starting position is disposed between symbol #Kand symbol #(K+N).

This is because PUSCH transmission can start in any symbol constitutinga slot through an SLIV in NR although the aforementioned situation neednot be considered in conventional systems (e.g., LAA) because there arefour PUSCH starting positions between Symbol #0 and Symbol #1 and thus astarting position before Symbol #0 is a symbol in a previous subframepassing a subframe boundary.

Here, a TBS may be determined depending on whether the reference symbolis identical to a symbol indicated by SLIV. The TBS can be determined onthe basis of Symbol #(K+N) when the symbols are identical and determinedon the basis of Symbol #K when the symbols are different. Here, the TBScan be determined on the basis of Symbol #K if the starting position isSymbol #K.

Basically, whether an eNB indicates a starting position between Symbol#(K-N) and Symbol #K or a starting position between Symbol #K and Symbol#(K+N) is not dynamically changed, and an accurate starting position maybe indicated through DCI in a state in which starting positioncandidates are semi-statically determined (The claims of the presentdisclosure may include dynamic change of whether an eNB indicates astarting position between Symbol #(K-N) and Symbol #K or a startingposition between Symbol #K and Symbol #(K+N)).

More specifically, the following examples can be provided.

(1) When a starting symbol index indicated by SLIV is symbol #K which isidentical to a reference symbol index when a PUSCH starting position isindicated, the UE can determine a TBS of a PUSCH on the basis of symbol#(K+N).

In other words, when the starting symbol index indicated by SLIV issymbol #K and the reference symbol index is symbol #K (because the PUSCHstarting position is between symbol #K and symbol #(K+N)) and thus thestarting symbol index and the reference symbol index correspond to eachother, the UE can determine the TBS of the PUSCH on the basis of symbol#(K+N).

(2) When a starting symbol index indicated by SLIV is symbol #K and areference symbol index when a PUSCH starting position is indicated issymbol #(K-N), the UE may determine the TBS of the PUSCH on the basis ofsymbol #K.

In other words, when the starting symbol index indicated by SLIV issymbol #K and the reference symbol index is symbol #(K-N) (because thePUSCH starting position is between symbol #(K-N) and symbol #K), the UEcan determine the TBS of the PUSCH on the basis of symbol #K.

(3) When a starting symbol index indicated by SLIV is symbol #K, alength (transmission duration) is and the starting symbol index isidentical to a reference symbol index when a PUSCH starting position isindicated, the UE may determine the TBS of the PUSCH on the basis ofsymbol #K and transmit the PUSCH by a length to symbol #(K+L+N)(however, this method may be applicable only when at least one symbolavailable after symbol #(K+L) is present in a slot).

In other words, when the starting symbol index indicated by SLIV issymbol #K, the length (transmission duration) is L, and the referencesymbol index is symbol #K (because the PUSCH starting position isbetween symbol #K and symbol #(K+N)) and thus the starting symbol indexand the reference symbol index correspond to each other, the UE candetermine the TBS of the PUSCH on the basis of symbol #(K+N) andtransmit the PUSCH by a length to symbol #(K+L+N).

However, the reference symbol index may be symbol #(K-N) or symbol #Kwhen the starting symbol index indicated by SLIV is symbol #K, and thismethod may be applicable only when at least one symbol available aftersymbol #K is present in a slot when the reference symbol index is symbol#(K-N).

In addition, N may be predefined as a specific value (e.g., N=1),additionally set/indicated through RRC signaling (or through DCI or acombination of RRC and DCI), or scalably set by an eNB for a UE asdifferent values according to numerologies.

FIG. 15 schematically illustrates an example of PUSCH starting positioncandidates considering an LBT type and a subcarrier spacing.

When a starting symbol index indicated by SLIV is symbol #K, PUSCHstarting position candidates considering an LBT type and a subcarrierspacing may be defined as {symbol #(K-N)+16 μs, symbol #(K-N)+16 μs+TA,symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA, symbol #K} or {symbol #K,symbol #K+16 μs, symbol #K+16 μs+TA, symbol #K+25 μs, symbol #K+25μs+TA}, as illustrated in FIG. 8.

Here, N may be predefined, additionally set/indicated through RRCsignaling (or through DCI or a combination of RRC and DCI), or scalablyset by an eNB for a UE as different values according to numerologies.

For example, N may be 1 when a subcarrier spacing is 15 kHz or 30 kHzand N may be 2 when the subcarrier spacing is 60 kHz. In addition,starting position candidates passing 1 or 2 symbol boundaries from thestarting symbol index indicated by SLIV may be excluded depending on asubcarrier spacing.

In this case, the reference symbol index is symbol #(K-N) or symbol #K,and a PUSCH transmission starting time is determined between symbol#(K-N) and symbol #K in the former case and determined as one ofcandidates between symbol #K and symbol #(K+N) depending on an LBT typeand SCS in the latter case.

Meanwhile, when symbol (0+25 μs) or symbol (0+25 μs+TA) (except symbol 0and symbol 1) is indicated as a PUSCH starting position, for example,and LBT is successfully performed, a gap between the PUSCH startingposition and symbol 1 may be filled by CP extension copying CP of symbol1.

The above embodiment may be extended and applied in NR-U. CP extensionmay be required in a gap between an actual PUSCH starting position andthe next symbol boundary depending on a subcarrier spacing. Here, CPextension cannot exceed 1 symbol length on the basis of the SCS, forexample.

In other words, CP extension can be applied to a gap between a PUSCHstarting position and the next symbol boundary on the basis of asubcarrier spacing. That is, a UE may copy CP (with respect to the firstsymbol of the PUSCH) and fill CP extension in the gap between the actualPUSCH starting position (from among multiple PUSCH starting positioncandidates) and the next symbol boundary. Here, CP extension can exceed1 symbol length as described above.

More specifically, when the reference symbol index is symbol #(K-N), agap between a position determined as an actual starting position fromamong candidates between #(K-N) and symbol #K (or between symbol #K andsymbol #(K+N) when the reference symbol index is symbol #K) and symbol#K (or symbol #(K+N)) is filled through CP extension (etc.) of the firstsymbol of the PUSCH. Here, the PUSCH symbol length and the value N maydepend on a subcarrier spacing, as described above.

Accordingly, the TBS of the PUSCH may be determined based ontime-frequency resources from symbol #(K+N) to symbol #(K+N+L) when thestarting symbol index indicated by SLIV is identical to the referencesymbol index as in (1), and the TBS of the PUSCH may be determined basedon time-frequency resources from symbol #K to symbol #(K+L) in the caseof (2). Alternatively, the PUSCH TBS may be determined on the basis ofsymbol #K and the PUSCH may be transmitted by a length to symbol#(K+L+N) as in (3). However, this method may be applicable only when atleast one symbol available after symbol #(K+L) is present in a slot.

In addition, the PUSCH symbol length and the value N may depend on asubcarrier spacing, as described above. Accordingly, if N is greaterthan 1 and CP extension equal to or greater than 1 symbol length of thePUSCH is required at a specific subcarrier spacing, an actual PUSCHstarting position may be regarded as a closest starting candidate thatdoes not exceed 1 symbol length and rate matching or TBS calculation maybe performed.

For example, in the case of a PUSCH with a subcarrier spacing of 60 kHz,N=2 and the reference symbol index is symbol #(K−2). Here, when thePUSCH starting position becomes symbol #(K−2)+16 μs, actual CP extensionbecomes greater than 1 symbol length of the PUSCH, and thus symbol#(K−1) may be regarded as an actual PUSCH starting position andrate-matching or TBS calculation may be performed.

As another example, when the reference symbol index is symbol #K, if theactual PUSCH starting position is symbol #K+16 μs since N=2 when SCS=60kHz, rate matching or TBS may be determined on the basis of symbol#(K+1) instead of symbol #(K+2).

3. Third Method

A method through which a UE performs LBT depending on an LBT typeindicated by a gNB and performs UL transmission in a gap between twoconsecutive transmissions (UL-to-UL or DL-to-UL) when the gap is X μs(X=16 μs or 25 μs) in a gNB-initiated channel occupancy time (CPT) maybe provided.

If LBT type 2 or 3 is possible in a 16 μs gap in addition to four PUSCHstarting candidates (symbol 0, symbol 0+25 μs, symbol 0+25 μs+TA,symbol 1) and two LBT types (type 1 and type 2) that can be indicated inlegacy eLAA, PUSCH starting position candidates that can be indicatedthrough a UL grant are as follows as in the aforementioned [proposedmethod #1].

That is, when a symbol indicated through SLIV is #K, available PUSCHstarting position candidates may be defined as {symbol #(K-N)+16 μs,symbol #(K-N)+16 μs+TA, symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA,symbol #K} or {symbol #K, symbol #K+16 μs, symbol #K+16 μs+TA, symbol#K+25 μs, symbol #K+25 μs+TA}, and {symbol #(K−1)+16 μs+TA} or {symbol#K+16 μs+TA} may be replaced with {symbol #(K−1)+max(16 μs, TZ)} or{symbol #K+max(16 μs, TA)}.

Here, when DL transmission is performed until a symbol immediatelybefore a PUSCH transmission starting symbol and then TA is present inthe first symbol of the next slot (e.g., when UL transmission startsimmediately after (16 μs-TA) from DL reception), {symbol #(K−1)+16μs+TA} or {symbol #K+16 μs+TA} may be excluded from the PUSCH startingposition candidates.

An example of a field configuration may be as shown in Table 5 and Table6.

TABLE 5 State LBT type or symbol #K 1 LBT type 1 2 LBT type 2 3 LBT type3 4 Symbol #K

TABLE 6 LBT type parsing when State PUSCH starting position symbol #K isindicated 1 Symbol #K + 25 μs LBT type 1 2 Symbol #K + 25 μs + TA LBTtype 2 3 Symbol #K + 16 μs LBT type 2 4 Symbol #K + 16 μs + TA LBT type3

As shown in Table 5 and Table 6, all LBT types can be indicated forsymbol #K among the PUSCH starting position candidates, LBT types 2 and3 can be indicated for {symbol #K+16 μs, symbol #K+16 μs+TA}, and LBTtypes 1 and 2 can be indicated for {symbol #K+25 μs, symbol #K+25μs+TA}, and thus three LBT types and five PUSCH starting positions canbe indicated to a UE using a total of four bits if the three LBT typesor symbol #K are indicated using a 2-bit field in a UL grant and one ofthe four PUSCH starting positions is indicated using another 2-bitfield.

That is, a PUSCH starting position is interpreted as indicated when theLBT type field indicates LBT type 1, 2, or 3 and a PUSCH startingposition field is reinterpreted as an LBT type when the LBT type fieldindicates symbol #K so that, when the second field indicates ‘state 1’,the UE can interpret this as LBT type 1, interpret symbol #K+25 μs+TA asLBT type 2, interpret symbol #K+16 μs as LBT type 2, and interpretsymbol #K+16 μs+TA as LBT type 3.

Further, the UE does not expect indication of a PUSCH starting positionthat does not correspond to an LBT type. That is, when a PUSCH startingpoint is {symbol #K+25 μs} or {symbol #K+25 μs+TA} although LBT type 3is indicated, the UE can regard the corresponding UL grant as invalidand ignore or drop the corresponding scheduling.

Similarly, when a PUSCH starting position is {symbol #(K-N)+16 μs,symbol #(K-N)+16 μs+TA, symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA}, ULgrant fields may be configured as shown in Table 7 and Table 8 asfollows to indicate LBT types.

TABLE 7 State LBT type or symbol #K 1 LBT type 1 2 LBT type 2 3 LBT type3 4 Symbol #K

TABLE 8 LBT type parsing when State PUSCH starting position symbol #K isindicated 1 Symbol #(K − N) + 25 μs LBT type 1 2 Symbol #(K − N) + 25μs + TA LBT type 2 3 Symbol #(K − N) + 16 μs LBT type 2 4 Symbol #(K −N) + 16 μs + TA LBT type 3

The eNB can indicate or set in advance, to the UE, whether a PUSCHstarting position is {symbol #(K-N)+16 μs, symbol #(K-N)+16 μs+TA,symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA, symbol #K} or {symbol #K,symbol #K+16 μs, symbol #K+16 μs+TA, symbol #K+25 μs, symbol #K+25μs+TA} on the basis of symbol #K indicated through SLIV.

As another method, a combination of an LBT type and a PUSCH startingposition may be defined as a state and indicated to the UE through a4-bit field in the UL grant, as shown in Table 9.

TABLE 9 State LBT type PUSCH starting position 0 1 (Cat4) Symbol #K 1 1Symbol #K + 16 μs 2 1 Symbol #K + 16 μs + TA 3 1 Symbol #K + 25 μs 4 1Symbol #K + 25 μs + TA 5 1 Symbol #(K + N) 6 2 (Cat2) Symbol #K 7 2Symbol #K + 16 μs 8 2 Symbol #K + 16 μs + TA 9 2 Symbol #K + 25 μs 10  2Symbol #K + 25 μs + TA 11  2 Symbol #(K + N) 12  3 (Cat1) Symbol #K 13 3 Symbol #K + 16 μs 14  3 symbol #K + 16 μs + TA 15  3 Symbol #(K + N)

In Table 9, states 1, 7, and 13 expressed in thick letters may beomitted because the length of one OFDM symbol is 16.67 μs when asubcarrier spacing of the PUSCH is 60 kHz.

In addition, transmission is immediately performed without CCA in thecase of LBT type 3, and thus {symbol #K+16 μs+TA} of state 14 expressedin italic letters may not be required.

Further, the value N of underlined states 5, 11, and 15 may bepredefined as a specific value (e.g., N=1), additionally set/indicatedthrough RRC signaling (or through DCI or a combination of RRC and DCI),or scalably set by an eNB for a UE as different values according tonumerologies.

For example, N=1 when a subcarrier spacing (SCS) is 15 kHz and N=2 whenthe SCS is 30 kHz.

Alternatively, when the SCS is greater than 15 kHz, a starting positionpassing the next symbol boundary of symbol #K from among {symbol #K+16μs, symbol #K+25 μs, symbol #K+25 μs+TA} and a starting position passingthe previous symbol boundary of symbol #(K−1) from among {symbol#(K−1)+16 μs, symbol #(K-N)+25 μs, symbol #(K-N)+25 μs+TA, symbol #K}may be excluded.

The contents of FIG. 8 described above will be described below from theviewpoint of a UE.

FIG. 16 is a flowchart of a method for performing, by a UE, an operationdepending on an LBT type in an unlicensed band according to anembodiment of the present disclosure.

Referring to FIG. 16, the UE may acquire, from an eNB, information aboutthe LBT type and information about a physical uplink shared channel(PUSCH) starting position through a UL grant (S1610). Here, theinformation about the PUSCH starting position may be informationindicating any one position among a plurality of PUSCH starting positioncandidates. Here, a specific example in which the UE acquires theinformation about the LBT type and the information about the PUSCHstarting position has been described above.

Subsequently, the UE may perform an operation depending on the LBT typeon the basis of the acquired LBT type (S1620). Here, a specific examplein which the UE performs the operation depending on the LBT type hasbeen described above.

After execution of the operation depending on the LBT type, the UE maytransmit a PUSCH on the basis of the information about the PUSCHstarting position (S1630). A specific example in which the UE transmitsthe PUSCH on the basis of the information about the PUSCH startingposition after execution of the operation depending on the LBT type hasbeen described above.

FIG. 17 is a block diagram illustrating an example of an apparatus forperforming, by a UE, an operation depending on an LBT type in anunlicensed band according to an embodiment of the present disclosure.

Referring to FIG. 17, a processor 1700 may include an informationacquisition unit 1710, an operation execution unit 1720, and atransmission execution unit 1730. Here, the processor may refer to aprocessor in FIG. 20 to FIG. 28 which will be described later.

The information acquisition unit 1710 may be configured to acquire, froman eNB, information about the LBT type and information about a physicaluplink shared channel (PUSCH) starting position through a UL grant.Here, the information about the PUSCH starting position may beinformation indicating any one position among a plurality of PUSCHstarting position candidates. Here, a specific example in which the UEacquires the information about the LBT type and the information aboutthe PUSCH starting position has been described above.

Subsequently, the operation execution unit 1720 may be configured toperform an operation depending on the LBT type on the basis of theacquired LBT type. Here, a specific example in which the UE performs theoperation depending on the LBT type has been described above.

The transmission execution unit 1730 may be configured to transmit aPUSCH on the basis of the information about the PUSCH starting positionafter execution of the operation depending on the LBT type. A specificexample in which the UE transmits the PUSCH on the basis of theinformation about the PUSCH starting position after execution of theoperation depending on the LBT type has been described above.

The contents of FIG. 8 described above will be described below from theviewpoint of an eNB.

FIG. 18 is a flowchart of a method for indicating an LBT type by an eNBaccording to an embodiment of the present disclosure.

Referring to FIG. 18, the eNB may transmit, to a UE, information aboutthe LBT type and information about a physical uplink shared channel(PUSCH) starting position through a UL grant (S1810). Here, theinformation about the PUSCH starting position may be informationindicating any one position among a plurality of PUSCH starting positioncandidates. Here, a specific example in which the eNB transmits theinformation about the LBT type and the information about the PUSCHstarting position has been described above.

The eNB may receive a PUSCH from the UE (S1820). A specific example inwhich the eNB receives the PUSCH from the UE has been described above.

FIG. 19 is a block diagram illustrating an example of an apparatus forindicating an LBT type by an eNB according to an embodiment of thepresent disclosure.

Referring to FIG. 19, a processor 1900 may include an informationtransmitter 1910 and a receiver 1920. Here, the processor may refer tothe processor in FIG. 20 to FIG. 28 which will be described later.

The information transmitter 1910 may be configured to transmit, to a UE,information about the LBT type and information about a physical uplinkshared channel (PUSCH) starting position through a UL grant. Here, theinformation about the PUSCH starting position may be informationindicating any one position among a plurality of PUSCH starting positioncandidates. Here, a specific example in which the eNB transmits theinformation about the LBT type and the information about the PUSCHstarting position has been described above.

The receiver 1920 may be configured to receive a PUSCH from the UE. Aspecific example in which the eNB receives the PUSCH from the UE hasbeen described above.

FIG. 20 illustrates a UE for implementing embodiments of the presentdisclosure. The present disclosure described above with respect to theUE is applicable to this embodiment.

The UE 600 includes a processor 610, a memory 620, and a transceiver630. The processor 610 may be configured to implement functions,procedures and/or methods proposed in the present specification. Layersof a wireless interface protocol may be implemented in the processor610.

More specifically, the processor 610 may include the informationacquisition unit 1710, the operation execution unit 1720, and thetransmission execution unit 1730.

The information acquisition unit 1710 may be configured to acquire, froman eNB, information about the LBT type and information about a physicaluplink shared channel (PUSCH) starting position through a UL grant.Here, the information about the PUSCH starting position may beinformation indicating any one position among a plurality of PUSCHstarting position candidates. Here, a specific example in which the UEacquires the information about the LBT type and the information aboutthe PUSCH starting position has been described above.

Subsequently, the operation execution unit 1720 may be configured toperform an operation depending on the LBT type on the basis of theacquired LBT type. Here, a specific example in which the UE performs theoperation depending on the LBT type has been described above.

The transmission execution unit 1730 may be configured to transmit aPUSCH on the basis of the information about the PUSCH starting positionafter execution of the operation depending on the LBT type. A specificexample in which the UE transmits the PUSCH on the basis of theinformation about the PUSCH starting position after execution of theoperation depending on the LBT type has been described above.

The memory 620 is operatively coupled with the processor 610 and storesa variety of information to operate the processor 610. The transceiver630 is operatively coupled with the processor 610, and transmits and/orreceives a radio signal.

The processor 610 may include application-specific integrated circuit(ASIC), other chipset, logic circuit and/or data processing device. Thememory 620 may include read-only memory (ROM), random access memory(RAM), flash memory, memory card, storage medium and/or other storagedevice. The transceiver 630 may include baseband circuitry to processradio frequency signals. When the embodiments are implemented insoftware, the techniques described herein can be implemented withmodules (e.g., procedures, functions, and so on) that perform thefunctions described herein. The modules can be stored in the memory 620and executed by the processor 610. The memory 620 can be implementedwithin the processor 610 or external to the processor 610 in which casethose can be communicatively coupled to the processor 610 via variousmeans as is known in the art.

FIG. 21 illustrates a UE for implementing embodiments of the presentdisclosure in more detail.

The present disclosure described above with respect to the UE isapplicable to this embodiment.

A UE includes a processor 610, a power management module 611, a battery612, a display 613, a keypad 614, a subscriber identification module(SIM) card 615, a memory 620, a transceiver 630, one or more antennas631, a speaker 640, and a microphone 641.

The processor 610 may be configured to implement proposed functions,procedures and/or methods described in this description. Layers of theradio interface protocol may be implemented in the processor 610. Theprocessor 610 may include ASIC, other chipset, logic circuit and/or dataprocessing device. The processor 610 may be an application processor(AP). The processor 610 may include at least one of a digital signalprocessor (DSP), a central processing unit (CPU), a graphics processingunit (GPU), a modem (modulator and demodulator). An example of theprocessor 610 may be found in SNAPDRAGON™ series of processors made byQualcomm®, EXYNOS™ series of processors made by Samsung®, A series ofprocessors made by Apple®, HELIO™ series of processors made byMediaTek®, ATOM™ series of processors made by Intel® or a correspondingnext generation processor.

More specifically, the processor 610 may include the above-describedinformation acquisition unit 1710, the operation execution unit 1720,and the transmission execution unit 1730.

The information acquisition unit 1710 may be configured to acquire, froman eNB, information about the LBT type and information about a physicaluplink shared channel (PUSCH) starting position through a UL grant.Here, the information about the PUSCH starting position may beinformation indicating any one position among a plurality of PUSCHstarting position candidates. Here, a specific example in which the UEacquires the information about the LBT type and the information aboutthe PUSCH starting position has been described above.

Subsequently, the operation execution unit 1720 may be configured toperform an operation depending on the LBT type on the basis of theacquired LBT type. Here, a specific example in which the UE performs theoperation depending on the LBT type has been described above.

The transmission execution unit 1730 may be configured to transmit aPUSCH on the basis of the information about the PUSCH starting positionafter execution of the operation depending on the LBT type. A specificexample in which the UE transmits the PUSCH on the basis of theinformation about the PUSCH starting position after execution of theoperation depending on the LBT type has been described above.

The power management module 611 manages power for the processor 610and/or the transceiver 630. The battery 612 supplies power to the powermanagement module 611. The display 613 outputs results processed by theprocessor 610. The keypad 614 receives inputs to be used by theprocessor 610. The keypad 614 may be shown on the display 613. The SIMcard 615 is an integrated circuit that is intended to securely store theinternational mobile subscriber identity (IMSI) number and its relatedkey, which are used to identify and authenticate subscribers on mobiletelephony devices (such as mobile phones and computers). It is alsopossible to store contact information on many SIM cards.

The memory 620 is operatively coupled with the processor 610 and storesa variety of information to operate the processor 610. The memory 620may include ROM, RAM, flash memory, memory card, storage medium and/orother storage device. When the embodiments are implemented in software,the techniques described herein can be implemented with modules (e.g.,procedures, functions, and so on) that perform the functions describedherein. The modules can be stored in the memory 620 and executed by theprocessor 610. The memory 620 can be implemented within the processor610 or external to the processor 610 in which case those can becommunicatively coupled to the processor 610 via various means as isknown in the art.

The transceiver 630 is operatively coupled with the processor 610, andtransmits and/or receives a radio signal. The transceiver 630 includes atransmitter and a receiver. The transceiver 630 may include basebandcircuitry to process radio frequency signals. The transceiver 630controls the one or more antennas 631 to transmit and/or receive a radiosignal.

The speaker 640 outputs sound-related results processed by the processor610. The microphone 641 receives sound-related inputs to be used by theprocessor 610.

FIG. 22 illustrates a network node for implementing embodiments of thepresent disclosure.

The present disclosure described above with respect to a network isapplicable to this embodiment.

The network node 800 includes a processor 810, a memory 820, and atransceiver 830. The processor 810 may be configured to implementfunctions, procedures and/or methods proposed in the presentspecification. Layers of a wireless interface protocol may beimplemented in the processor 810.

More specifically, the processor 810 may include the above-describedinformation transmitter 1910 and a receiver 1920.

The information transmitter 1910 may be configured to transmit, to a UE,information about the LBT type and information about a physical uplinkshared channel (PUSCH) starting position through a UL grant. Here, theinformation about the PUSCH starting position may be informationindicating any one position among a plurality of PUSCH starting positioncandidates. Here, a specific example in which an eNB transmits theinformation about the LBT type and the information about the PUSCHstarting position has been described above.

The receiver 1920 may be configured to receive a PUSCH from the UE. Aspecific example in which the eNB receives the PUSCH from the UE hasbeen described above.

The memory 820 is operatively coupled with the processor 810 and storesa variety of information to operate the processor 810. The transceiver830 is operatively coupled with the processor 810, and transmits and/orreceives a radio signal.

The processor 810 may include ASIC, other chipset, logic circuit and/ordata processing device. The memory 820 may include ROM, RAM, flashmemory, memory card, storage medium and/or other storage device. Thetransceiver 830 may include baseband circuitry to process radiofrequency signals. When the embodiments are implemented in software, thetechniques described herein can be implemented with modules (e.g.,procedures, functions, and so on) that perform the functions describedherein. The modules can be stored in the memory 820 and executed by theprocessor 810. The memory 820 can be implemented within the processor810 or external to the processor 810 in which case those can becommunicatively coupled to the processor 810 via various means as isknown in the art.

FIG. 23 illustrates an example of a signal processing module structurein a transmission apparatus. Here, signal processing may be performed ina processor of an eNB/UE, such as the processor of FIGS. 20 to 22.

Referring to FIG. 23, a transmission apparatus 1810 in a UE or an eNBmay include a scrambler 301, a modulator 302, a layer mapper 303, anantenna port mapper 304, a resource block mapper 305, and a signalgenerator 306.

The transmission apparatus 1810 may transmit one or more codewords.Coded bits in each codeword are scrambled by the scrambler 301 andtransmitted on a physical channel. A codword may be called a data streamand may be equivalent to a transport block that is a data block providedby the MAC layer.

The scrambled bits are modulated into complex-valued modulation symbolsby the modulator 302. The modulator 302 may modulate the scrambled bitsaccording to a modulation scheme and dispose them as complex-valuedmodulation symbols representing positions on a signal constellation. Themodulation scheme is not limited, and m-Phase Shift Keying (m-PSK) orm-Quadrature Amplitude Modulation (m-QAM) may be used to modulate thecoded data. The modulator may be referred to as a modulation mapper.

The complex-valued modulation symbols may be mapped to one or moretransport layers by the layer mapper 303. A complex-valued modulationsymbol on each layer may be mapped by the antenna port mapper 304 fortransmission on an antenna port.

The resource block mapper 305 may map a complex-valued modulation symbolfor each antenna port to an appropriate resource element in a virtualresource block allocated for transmission. The resource block mapper maymap the virtual resource block to a physical resource block through anappropriate mapping scheme. The resource block mapper 305 may allocatethe complex-valued modulation symbol for each antenna port to anappropriate subcarrier and multiplex it according to a user.

The signal generator 306 may modulate the complex-valued modulationsymbol for each antenna port, that is, an antenna-specific symbolthrough a specific modulation scheme, for example, Orthogonal FrequencyDivision Multiplexing (OFDM) to generate a complex-valued time domainOFDM symbol signal. The signal generator may perform Inverse FastFourier Transform (IFFT) on the antenna-specific symbol, and a cyclicprefix (CP) may be inserted into the time-domain symbol on which IFFThas been performed. OFDM symbols are subjected to digital-to-analogconversion and frequency upconversion and transmitted to a receptionapparatus through each transmission antenna. The signal generator mayinclude an IFFT module, a CP insertion unit, a digital-to-analogconverter (DAC), and a frequency uplink converter.

FIG. 24 illustrates another example of a signal processing modulestructure in a transmission apparatus. Here, signal processing may beperformed in a processor of an eNB/UE, such as the processor of FIGS. 20to 23.

Referring to FIG. 24, the transmission apparatus 1810 in a UE or an eNBmay include a scrambler 401, a modulator 402, a layer mapper 403, aprecoder 404, a resource block mapper 405, and a signal generator 406.

The transmission apparatus 1810 may scramble coded bits in a codewordthrough the scrambler 401 and then transmit the scrambled coded bitsthrough a physical channel.

The scrambled bits are modulated into complex-valued modulation symbolsby the modulator 402. The modulator may modulate the scrambled bitsaccording to a predetermined modulation scheme and dispose them ascomplex-valued modulation symbols representing positions on a signalconstellation. The modulation scheme is not limited, and pi/2-BinaryPhase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK) orm-Quadrature Amplitude Modulation (m-QAM) may be used to modulate thecoded data.

The complex-valued modulation symbols may be mapped to one or moretransport layers by the layer mapper 403.

A complex-valued modulation symbol on each layer may be precoded by theprecoder 404 for transmission on an antenna port. Here, the precoder mayperform transform precoding on the complex-valued modulation symbol andthen perform precoding thereon. Alternatively, the precoder may performprecoding without performing transform precoding. The precoder 404 mayprocess the complex-valued modulation symbols through MIMO according tomultiple transmission antennas to output antenna-specific symbols anddistribute the antenna-specific symbols to the resource block mapper405. An output z of the precoder 404 can be obtained by multiplying anoutput y of the layer mapper 403 by an N×M precoding matrix. Here, N isthe number of antenna ports and M is the number of layers.

The resource block mapper 405 maps the complex-valued modulation symbolfor each antenna port to an appropriate resource element in a virtualresource block allocated for transmission.

The resource block mapper 405 may allocate the complex-valued modulationsymbol to an appropriate subcarrier and multiplex it according to auser.

The signal generator 406 may modulate the complex-valued modulationsymbols through a specific modulation scheme, for example, OFDM togenerate a complex-valued time domain OFDM symbol signal. The signalgenerator 406 may perform IFFT on antenna-specific symbols, and a CP maybe inserted into the time-domain symbols on which IFFT has beenperformed. OFDM symbols are subjected to digital-to-analog conversionand frequency upconversion and transmitted to a reception apparatusthrough each transmission antenna. The signal generator 406 may includean IFFT module, a CP insertion unit, a digital-to-analog converter(DAC), and a frequency uplink converter.

A signal processing procedure of a reception apparatus 1820 may be areverse to the signal processing procedure of the transmissionapparatus. Specifically, a processor 1821 of the reception apparatus1820 performs decoding and demodulation on an RF signal received fromthe outside through antenna port(s) of a transceiver 1822. The receptionapparatus 1820 may include multiple reception antennas, and signalsreceived through the reception antennas are restored to baseband signalsand then reconstructed to a data stream originally intended to betransmitted by the transmission apparatus 1810 through multiplexing andMIMO demodulation. The reception apparatus 1820 may include a signalrestoration unit for restoring a received signal to a baseband signal, amultiplexer for combining and multiplexing the received signal, and achannel demodulator for demodulating a multiplexed signal sequence intoa codeword. The signal restoration unit, the multiplexer, and thechannel demodulator may be configured as an integrated module orindependent modules for executing functions thereof. More specifically,the signal restoration unit may include an analog-to-digital converter(ADC) for converting an analog signal into a digital signal, a CPremoval unit for removing a CP from the digital signal, an FFT modulefor applying fast Fourier transform (FFT) to the CP-removed signal tooutput frequency domain symbols, and a resource elementdemapper/equalizer for restoring the frequency domain symbols toantenna-specific symbols. The antenna-specific symbols are restored totransport layers by the multiplexer, and the transport layers arerestored to codewords that the transmission apparatus intends totransmit.

The above-described embodiments of the present disclosure may also beapplied to the following situations.

FIG. 25 shows examples of 5G usage scenarios to which the technicalfeatures of the present document can be applied.

The 5G usage scenarios shown in FIG. X are only exemplary, and thetechnical features of the present document can be applied to other 5Gusage scenarios which are not shown in FIG. 25.

Referring to FIG. 25, the three main requirements areas of 5G include(1) enhanced mobile broadband (eMBB) domain, (2) massive machine typecommunication (mMTC) area, and (3) ultra-reliable and low latencycommunications (URLLC) area. Some use cases may require multiple areasfor optimization and, other use cases may only focus on only one keyperformance indicator (KPI). 5G is to support these various use cases ina flexible and reliable way.

eMBB focuses on across-the-board enhancements to the data rate, latency,user density, capacity and coverage of mobile broadband access. The eMBBaims ˜10 Gbps of throughput. eMBB far surpasses basic mobile Internetaccess and covers rich interactive work and media and entertainmentapplications in cloud and/or augmented reality. Data is one of the keydrivers of 5G and may not be able to see dedicated voice services forthe first time in the 5G era. In 5G, the voice is expected to beprocessed as an application simply using the data connection provided bythe communication system. The main reason for the increased volume oftraffic is an increase in the size of the content and an increase in thenumber of applications requiring high data rates. Streaming services(audio and video), interactive video and mobile Internet connectivitywill become more common as more devices connect to the Internet. Many ofthese applications require always-on connectivity to push real-timeinformation and notifications to the user. Cloud storage andapplications are growing rapidly in mobile communication platforms,which can be applied to both work and entertainment. Cloud storage is aspecial use case that drives growth of uplink data rate. 5G is also usedfor remote tasks on the cloud and requires much lower end-to-end delayto maintain a good user experience when the tactile interface is used.In entertainment, for example, cloud games and video streaming areanother key factor that increases the demand for mobile broadbandcapabilities. Entertainment is essential in smartphones and tabletsanywhere, including high mobility environments such as trains, cars andairplanes. Another use case is augmented reality and informationretrieval for entertainment. Here, augmented reality requires very lowlatency and instantaneous data amount.

mMTC is designed to enable communication between devices that arelow-cost, massive in number and battery-driven, intended to supportapplications such as smart metering, logistics, and field and bodysensors. mMTC aims ˜10 years on battery and/or ˜1 million devices/km2.mMTC allows seamless integration of embedded sensors in all areas and isone of the most widely used 5G applications. Potentially by 2020, IoTdevices are expected to reach 20.4 billion. Industrial IoT is one of theareas where 5G plays a key role in enabling smart cities, assettracking, smart utilities, agriculture and security infrastructures.

URLLC will make it possible for devices and machines to communicate withultra-reliability, very low latency and high availability, making itideal for vehicular communication, industrial control, factoryautomation, remote surgery, smart grids and public safety applications.URLLC aims ˜1 ms of latency. URLLC includes new services that willchange the industry through links with ultra-reliability/low latency,such as remote control of key infrastructure and self-driving vehicles.The level of reliability and latency is essential for smart gridcontrol, industrial automation, robotics, drones control andcoordination.

Next, a plurality of use cases included in the triangle of FIG. 25 willbe described in more detail.

5G can complement fiber-to-the-home (FTTH) and cable-based broadband (orDOCSIS) as a means of delivering streams rated from hundreds of megabitsper second to gigabits per second. This high speed can be required todeliver TVs with resolutions of 4K or more (6K, 8K and above) as well asvirtual reality (VR) and augmented reality (AR). VR and AR applicationsinclude mostly immersive sporting events. Certain applications mayrequire special network settings. For example, in the case of a VR game,a game company may need to integrate a core server with an edge networkserver of a network operator to minimize delay.

Automotive is expected to become an important new driver for 5G, withmany use cases for mobile communications to vehicles. For example,entertainment for passengers demands high capacity and high mobilebroadband at the same time. This is because future users will continueto expect high-quality connections regardless of their location andspeed. Another use case in the automotive sector is an augmented realitydashboard. The driver can identify an object in the dark on top of whatis being viewed through the front window through the augmented realitydashboard. The augmented reality dashboard displays information thatwill inform the driver about the object's distance and movement. In thefuture, the wireless module enables communication between vehicles,information exchange between the vehicle and the supportinginfrastructure, and information exchange between the vehicle and otherconnected devices (e.g. devices accompanied by a pedestrian). The safetysystem allows the driver to guide the alternative course of action sothat he can drive more safely, thereby reducing the risk of accidents.The next step will be a remotely controlled vehicle or self-drivingvehicle. This requires a very reliable and very fast communicationbetween different self-driving vehicles and between vehicles andinfrastructure. In the future, a self-driving vehicle will perform alldriving activities, and the driver will focus only on traffic that thevehicle itself cannot identify. The technical requirements ofself-driving vehicles require ultra-low latency and high-speedreliability to increase traffic safety to a level not achievable byhumans.

Smart cities and smart homes, which are referred to as smart societies,will be embedded in high density wireless sensor networks. Thedistributed network of intelligent sensors will identify conditions forcost and energy-efficient maintenance of a city or house. A similarsetting can be performed for each home. Temperature sensors, windows andheating controllers, burglar alarms and appliances are all wirelesslyconnected. Many of these sensors typically require low data rate, lowpower and low cost. However, for example, real-time HD video may berequired for certain types of devices for monitoring.

The consumption and distribution of energy, including heat or gas, ishighly dispersed, requiring automated control of distributed sensornetworks. The smart grid interconnects these sensors using digitalinformation and communication technologies to collect and act oninformation. This information can include supplier and consumerbehavior, allowing the smart grid to improve the distribution of fuel,such as electricity, in terms of efficiency, reliability, economy,production sustainability, and automated methods. The smart grid can beviewed as another sensor network with low latency.

The health sector has many applications that can benefit from mobilecommunications. Communication systems can support telemedicine toprovide clinical care in remote locations. This can help to reducebarriers to distance and improve access to health services that are notcontinuously available in distant rural areas. It is also used to savelives in critical care and emergency situations. Mobile communicationbased wireless sensor networks can provide remote monitoring and sensorsfor parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly importantin industrial applications. Wiring costs are high for installation andmaintenance. Thus, the possibility of replacing a cable with a wirelesslink that can be reconfigured is an attractive opportunity in manyindustries. However, achieving this requires that wireless connectionsoperate with similar delay, reliability, and capacity as cables and thattheir management is simplified. Low latency and very low errorprobabilities are new requirements that need to be connected to 5G.

Logistics and freight tracking are important use cases of mobilecommunications that enable tracking of inventory and packages anywhereusing location based information systems. Use cases of logistics andfreight tracking typically require low data rates, but require a largerange and reliable location information.

Meanwhile, the above-described device may be a base station, a networknode, a transmitting terminal, a receiving terminal, a wireless device,a wireless communication device, a vehicle, a vehicle equipped with anautonomous driving function, a connected car, a unmanned aerial vehicle(UAV), an Artificial Intelligence (AI) module, a robot, an augmentedreality (AR) device, a virtual reality (VR) device, a mixed reality (MR)device, a hologram device, a public safety device, an machine typecommunication (MTC) device, an Internet of Things (IoT) device, amedical device, a pin-tec device (or financial device), a securitydevice, a climate/environmental device, devices related to 5G services,or other devices related to fourth industrial revolution fields.

For example, terminals may include a cellular phone, a smart phone, alaptop computer, a digital broadcasting terminal, a personal digitalassistants (PDA), a portable multimedia player (PMP), a navigationdevice, a slate PC, a tablet PC, an ultrabook, a wearable device (e.g.,a smartwatch, a smart glass, or a head mounted display (HMD)), etc. Forexample, the HMD may be a display device worn on a head. For example,the HMD may be used to implement the VR, AR, or MR.

For example, the UAV may be a flying object that is not ridden by peoplebut that flies by radio control signals. For example, the VR device mayinclude a device that implements an object or background in a virtualworld. For example, the AR device may include a device that connects andimplements the object or background in the real world to the object orbackground in a real world. For example, the MR device may include adevice that fuses and implements the object or background in the virtualworld with the object or background in the real world. For example, thehologram device may include a device for implementing a 360-degreestereoscopic image by recording and reproducing stereoscopic informationby utilizing a phenomenon of interference of light generated by the twolaser lights meeting with each other, called holography. For example,the public safety device may include a video relay device or a videodevice that may be worn by a body of a user. For example, the MTC deviceand the IoT device may be devices which do not require direct humanintervention or manipulation. For example, the MTC device and the IoTdevice may include a smart meter, a vending machine, a thermometer, asmart bulb, a door lock, or various sensors. For example, the medicaldevice may be a device used for diagnosing, treating, alleviating,treating, or preventing a disease. For example, the medical device maybe a device used for diagnosing, treating, alleviating, or correcting aninjury or disability. For example, the medical device may be a deviceused for inspecting, replacing, or modifying a structure or function.For example, the medical device may be a device used for controllingpregnancy. For example, the medical device may include a medicaltreatment device, a surgical device, an (in vitro) diagnostic device, ahearing aid or a (medical) procedure device, and the like. For example,the security device may be a device installed to prevent a risk that mayoccur and to maintain safety. For example, the security device may be acamera, a CCTV, a recorder, or a black box. For example, the pin-tecdevice may be a device capable of providing financial services such asmobile payment. For example, the pin-tec device may include a paymentdevice or a point of sales (POS). For example, the climate/environmentaldevice may include a device for monitoring or predicting aclimate/environment.

The above-described embodiments of the present disclosure may also beapplied to the following technologies.

<Artificial Intelligence (AI)>

Artificial intelligence refers to a field of study on artificialintelligence or methodologies for creating artificial intelligence, andmachine learning refers to a field of study on methodologies fordefining and solving various issues in the area of artificialintelligence. Machine learning is also defined as an algorithm forimproving the performance of an operation through steady experiences ofthe operation.

An artificial neural network (ANN) is a model used in machine learningand may refer to an overall problem-solving model that includesartificial neurons (nodes) forming a network by combining synapses. Theartificial neural network may be defined by a pattern of connectionbetween neurons of different layers, a learning process of updating amodel parameter, and an activation function generating an output value.

The artificial neural network may include an input layer, an outputlayer, and optionally one or more hidden layers. Each layer includes oneor more neurons, and the artificial neural network may include synapsesthat connect neurons. In the artificial neural network, each neuron mayoutput a function value of an activation function of input signals inputthrough a synapse, weights, and deviations.

A model parameter refers to a parameter determined through learning andincludes a weight of synapse connection and a deviation of a neuron. Ahyperparameter refers to a parameter to be set before learning in amachine learning algorithm and includes a learning rate, the number ofiterations, a mini-batch size, and an initialization function.

Learning an artificial neural network may be intended to determine amodel parameter for minimizing a loss function. The loss function may beused as an index for determining an optimal model parameter in a processof learning the artificial neural network.

Machine learning may be classified into supervised learning,unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of training an artificial neuralnetwork with a label given for training data, wherein the label mayindicate a correct answer (or result value) that the artificial neuralnetwork needs to infer when the training data is input to the artificialneural network. Unsupervised learning may refer to a method of trainingan artificial neural network without a label given for training data.Reinforcement learning may refer to a training method for training anagent defined in an environment to choose an action or a sequence ofactions to maximize a cumulative reward in each state.

Machine learning implemented with a deep neural network (DNN) includinga plurality of hidden layers among artificial neural networks isreferred to as deep learning, and deep learning is part of machinelearning. Hereinafter, machine learning is construed as including deeplearning.

<Robot>

Robots may refer to machinery that automatically process or operate agiven task with own ability thereof. In particular, a robot having afunction of recognizing an environment and autonomously making ajudgment to perform an operation may be referred to as an intelligentrobot.

Robots may be classified into industrial, medical, household, militaryrobots and the like according uses or fields.

A robot may include an actuator or a driver including a motor to performvarious physical operations, such as moving a robot joint. In addition,a movable robot may include a wheel, a brake, a propeller, and the likein a driver to run on the ground or fly in the air through the driver.

<Self-Driving, Autonomous-Driving)>

Self-driving refers to autonomous driving and a self-driving vehiclerefers to a vehicle that travels without user operation or with minimumoperation of a user.

For example, self-driving may include a technique of keeping a currentlane, a technique of automatically controlling a speed, such as adaptivecruise control, a technique of automatically traveling along a setroute, a technique of automatically setting a route and traveling alongthe route when a destination is set, etc.

Vehicles include vehicles equipped with only an internal combustionengine, hybrid vehicles equipped with an internal combustion engine andan electric motor, and electric vehicles equipped with only an electricmotor and may also include trains, motorcycles, etc.

Here, self-driving vehicles may be regarded as robots having aself-driving function.

<Extended Reality (XR)>

Extended reality collectively refers to virtual reality (VR), augmentedreality (AR), and mixed reality (MR). VR technology is a computergraphic technology of providing a real-world object and background onlyin a CG image, AR technology is a computer graphic technology ofproviding a virtual CG image on a real object image, and MR technologyis a computer graphic technology of providing virtual objects mixed andcombined with the real world.

MR technology is similar to AR technology in that a real object and avirtual object are displayed together. However, a virtual object is usedas a supplement to a real object in AR technology, whereas a virtualobject and a real object are used as equal statuses in MR technology.

XR technology may be applied to a head-mount display (HMD), a head-updisplay (HUD), a mobile phone, a tablet PC, a laptop computer, a desktopcomputer, a TV, digital signage, and the like. A device to which XRtechnology is applied may be referred to as an XR device.

FIG. 26 illustrates an AI device 100 according to an embodiment of thepresent disclosure.

The AI device 100 may be implemented by a fixed device or a mobiledevice such as a TV, a projector, a cellular phone, a smartphone, adesktop computer, a notebook computer, a digital broadcasting terminal,a personal digital assistant (PDA), a portable multimedia player (PMP),a navigation system, a table PC, a wearable device, a set-top box (STB),a DMB receiver, a radio receiver, a washing machine, a refrigerator, adigital signage, a robot, or a vehicle.

Referring to FIG. 26, the AI device 100 may include a communication unit110, an input unit 120, a learning processor 130, a sensing unit 140, anoutput unit 150, a memory 170, a processor 180, and the like.

The communication unit 110 may transmit/receive data to/from externaldevices such as other AI devices 100 a to 100 e or an AI server 200using wired and wireless communication technologies. For example, thecommunication unit 110 may transmit/receive sensor information, userinput, learning models, control signals, and the like to/from theexternal devices.

Here, communication technologies used by the communication unit 110 mayinclude GSM (Global System for Mobile communication), CDMA (CodeDivision Multi Access), LTE (Long Term Evolution), 5G, WLAN (WirelessLAN), Wi-Fi (Wireless-Fidelity), Bluetooth™ RFID (Radio FrequencyIdentification), IrDA (Infrared Data Association), ZigBee, NFC (NearField Communication), etc.

The input unit 120 may acquire various types of data.

Here, the input unit 120 may include a camera for receiving image signalinput, a microphone for receiving audio signals, a user input unit forreceiving information from a user, and the like. Here, the camera or themicrophone may be handled as a sensor and a signal acquired through thecamera or the microphone may be referred to as sensing data or sensinginformation.

The input unit 120 may acquire input data to be used when an output isobtained using learning data and a learning model for model learning.The input unit 120 may acquire unprocessed input data. In this case, theprocessor 180 or the learning processor 130 may extract input featuresby preprocessing the input data.

The learning processor 130 may train a model composed of an artificialneural network using learning data. Here, a trained artificial neuralnetwork may be referred to as a learning model. The learning model maybe used to infer result values with respect to new input data instead oflearning data, and inferred values may be used as a basis ofdetermination for performing a certain operation.

Here, the learning processor 130 may perform AI processing along with alearning processor 240 of the AI server 200.

Here, the learning processor 130 may include a memory that is integratedinto the AI device 100 or implemented. Alternatively, the learningprocessor 130 may be implemented using the memory 170, an externalmemory directly connected to the AI device 100, or a memory maintainedby an external device.

The sensing unit 140 may acquire at least one of internal information ofthe AI device 100, surrounding environment information of the AI device100, and user information using various sensors.

Here, sensors included in the sensing unit 140 include a proximitysensor, an illumination sensor, an acceleration sensor, a magneticsensor, a gyro sensor, an inertia sensor, an RGB sensor, an IR sensor, afingerprint recognition sensor, an ultrasonic sensor, an optical sensor,a microphone, a lidar, a radar, etc.

The output unit 150 may generate outputs associated with vision, hearingor tactile sensation.

Here, the output unit 150 may include a display for outputting visualinformation, a speaker for outputting auditory information, a hapticmodule for outputting tactile information, etc.

The memory 170 may store data supporting various functions of the AIdevice 100. For example, the memory 170 can store input data, learningdata, a learning model, and a learning history acquired through theinput unit 120.

The processor 180 may determine at least one executable operation of theAI device 100 on the basis of information determined or generated usinga data analysis algorithm or a machine learning algorithm. In addition,the processor 180 may perform the determined operation by controllingcomponents of the AI device 100.

To this end, the processor 180 may request, search, receive or use dataof the learning processor 130 or the memory 170 and control componentsof the AI device 100 such that a predicted operation or an operationdetermined to be desirable among the at least one executable operationis executed.

Here, when association with an external device is necessary to executethe determined operation, the processor 180 may generate a controlsignal for controlling the external device and transmit the generatedcontrol signal to the external device.

The processor 180 may acquire intention information with respect to auser input and determine requirements of a user on the basis of theacquired intention information.

Here, the processor 180 can acquire the intention informationcorresponding to the user input using at least one of a speech-to-text(STT) engine for converting a speech input into text and a naturallanguage processing (NLP) engine for acquiring intention information ofa natural language.

Here, at least a part of at least one of the STT engine and the NLPengine may be composed of an artificial neural network trained accordingto a machine learning algorithm. In addition, at least one of the STTengine and the NLP engine may be trained by the learning processor 130,trained by the learning processor 240 of the AI server 200, or trainedthrough distributed processing of the learning processor 130 and thelearning processor 240.

The processor 180 may collect history information including details ofoperations of the AI device 100 or user feedback with respect tooperations and store the history information in the memory 170 or thelearning processor 130 or transmit the history information to anexternal device such as the AI server 200. The collected historyinformation can be used to update the learning model.

The processor 180 may control at least some of the components of the AIdevice 100 in order to execute an application program stored in thememory 170. Furthermore, the processor 180 may combine at least two ofthe components included in the AI device 100 and operate the same inorder to execute the application program.

FIG. 27 illustrates the AI server 200 according to an embodiment of thepresent disclosure.

Referring to FIG. 27, the AI server 200 may refer to a device thattrains an artificial neural network using a machine learning algorithmor uses a trained artificial neural network. Here, the AI server 200 maybe composed of multiple servers to perform distributed processing andmay be defined as a 5G network. Here, the AI server 200 may be includedin the AI device 100 as a part of components thereof to perform at leasta part of AI processing.

The AI server 200 may include a communication unit 210, a memory 230,the learning processor 240, and a processor 260.

The communication unit 210 may transmit/receive data to/from externaldevices such as the AI device 100.

The memory 230 may include a model storage unit 231. The model storageunit 231 may store a model (or an artificial neural network 231 a) thatis being trained or has been trained through the learning processor 240.

The learning processor 240 may train the artificial neural network 231 ausing learning data. A learning model may be used in a state in which itis installed in the AI server 200 or used by being installed in anexternal device such as the AI device 100.

The learning model may be implemented by hardware, software, or acombination of hardware and software. When a part or all of the learningmodel is implemented by software, one or more instructions constitutingthe learning model may be stored in the memory 230.

The processor 260 may infer result values with respect to new input datausing the learning model and generate a response or a controlinstruction based on the inferred result values.

FIG. 28 illustrates an AI system 1 according to an embodiment of thepresent disclosure.

Referring to FIG. 28, in the AI system 1, at least one of the AI server200, a robot 100 a, a self-driving vehicle 100 b, an XR device 100 c, asmartphone 100 d, and a household electric appliance 100 e is connectedto a cloud network 10. Here, the robot 100 a, the self-driving vehicle100 b, the XR device 100 c, the smartphone 100 d, and the householdelectric appliance 100 e to which the AI technology is applied may bereferred to as AI devices 100 a to 100 e.

The cloud network 100 may refer to a network that constitutes a part ofa cloud computing infrastructure or is present in the cloud computinginfrastructure. Here, the cloud network 10 may be configured using a 3Gnetwork, a 4G or LTE (Long Term Evolution) network, or a 5G network.

That is, the devices 100 a to 100 e and 200 constituting the AI system 1can be connected through the cloud network 10. In particular, thedevices 100 a to 100 e and 200 may communicate with each other through abase station or directly communicate with each other without a basestation.

The AI server 200 may include a server performing AI processing and aserver performing arithmetic operations with respect to big data.

The AI server 200 may be connected to at least one of the robot 100 a,the self-driving vehicle 100 b, the XR device 100 c, the smartphone 100d and the household electric appliance 100 e which are AI devicesconstituting the AI system 1 through the cloud network 10 and may assistat least a part of AI processing of the connected AI devices 100 a to100 e.

Here, the AI server 200 may train an artificial neural network accordingto a machine learning algorithm instead of the AI devices 100 a to 100 eand directly store a learning model or transmit the learning model tothe AI devices 100 a to 100 e.

Here, the AI server 200 may receive input data from the AI devices 100 ato 100 e, infer result values with respect to the received input datausing the learning model, generate responses or control instructionsbased on the inferred result values, and transmit the responses or thecontrol instructions to the AI devices 100 a to 100 e.

Alternatively, the AI server 200 may directly infer result values withrespect to input data using the learning model and generate responses orcontrol instructions based on the inferred result values.

Hereinafter, various embodiments of the AI devices 100 a to 100 e towhich the above-described technology is applied will be described. Here,the AI devices 100 a to 100 e illustrated in FIG. 28 may be regarded asa specific embodiment of the AI device 100 illustrated in FIG. 1.

<AI+Robot>

The robot 100 a may be implemented as a guide robot, a transport robot,a cleaning robot, a wearable robot, an entertainment robot, a pet robot,an unmanned aircraft robot, or the like by employing the AI technology.

The robot 100 a may include a robot control module for controllingoperations, and the robot control module may refer to a software moduleor a chip that implements the software module as hardware.

The robot 100 a may acquire state information of the robot 100 a, detect(recognize) surrounding environments and objects, generate map data,determine a movement route and a traveling plan, determine a response toa user interaction, or determine an operation using sensor informationobtained from various types of sensors.

Here, the robot 100 a may use sensor information obtained from at leastone sensor of a lidar, a radar and a camera in order to determine amovement route and a traveling plan.

The robot 100 a may perform the aforementioned operations using alearning model composed of at least one artificial neural network. Forexample, the robot 100 a can recognize surrounding environments andobjects using the learning model and determine an operation usingrecognized surrounding environment information or object information.Here, the learning model may be directly trained in the robot 100 a ortrained in an external device such as the AI server 200.

Here, although the robot 100 a may directly generate results using thelearning model and perform an operation, the robot 100 a may transmitsensor information to an external device such as the AI server 200,receive results generated thereby and perform an operation.

The robot 100 a may determine a movement route and a traveling planusing at least one of object information detected from sensorinformation and object information acquired from an external device andtravel along the determined movement route according to the determinedtraveling plan by controlling a driver.

Map data may include object identification information about variousobjects disposed in a space in which the robot 100 a moves. For example,the map data may include object identification information about fixedobjects such as walls and doors and movable objects such as pots anddesks. In addition, object identification information may include names,types, distances, and positions.

In addition, the robot 100 a may perform an operation or travel bycontrolling the driver on the basis of control/interaction of a user.Here, the robot 100 a may acquire intention information of aninteraction according to motions or speech of the user, determine aresponse on the basis of the acquired intention information and performan operation.

<AI+Self-Driving>

The self-driving vehicle 100 b may be implement as a movable robot, avehicle, an unmanned aircraft, or the like by employing the AItechnology.

The self-driving vehicle 100 b may include a self-driving control modulefor controlling a self-driving function, and the self-driving controlmodule may refer to a software module or a chip that implements thesoftware module as hardware. The self-driving control module may beincluded in the self-driving vehicle 100 b as a component thereof or maybe configured as separate external hardware and connected to theself-driving vehicle 100 b.

The self-driving vehicle 100 b may acquire state information thereof,detect (recognize) surrounding environments and objects, generate mapdata, determine a movement route and a traveling plan, or determine anoperation using sensor information acquired from various types ofsensors.

Here, like the robot 100 a, the self-driving vehicle 100 b may usesensor information obtained from at least one sensor of a lidar, a radarand a camera in order to determine a movement route and a travelingplan.

In particular, the self-driving vehicle 100 b may recognize anenvironment or an object with respect to an unseen area or an area at acertain distance or longer by receiving sensor information from externaldevices or information directly recognized by the external devices.

The self-driving vehicle 100 b may perform the aforementioned operationsusing a learning model composed of at least one artificial neuralnetwork. For example, the self-driving vehicle 100 b can recognizesurrounding environments and objects using the learning model anddetermine a traveling route using recognized surrounding environmentinformation or object information. Here, the learning model may bedirectly trained in the self-driving vehicle 100 b or trained in anexternal device such as the AI server 200.

Here, although the self-driving vehicle 100 b may directly generateresults using the learning model and perform an operation, theself-driving vehicle 100 b may transmit sensor information to anexternal device such as the AI server 200, receive results generatedthereby and perform an operation.

The self-driving vehicle 100 b may determine a movement route and atraveling plan using at least one of object information detected fromsensor information and object information acquired from an externaldevice and travel along the determined movement route according to thedetermined traveling plan by controlling a driver.

Map data may include object identification information about variousobjects disposed in a space (e.g., roads) in which the self-drivingvehicle 100 b travels. For example, the map data may include objectidentification information about fixed objects such as streetlamps,rocks, and buildings and movable objects such as vehicles andpedestrians. In addition, object identification information may includenames, types, distances, and positions.

In addition, the self-driving vehicle 100 b may perform an operation ortravel by controlling the driver on the basis of control/interaction ofa user. Here, the self-driving vehicle 100 b may acquire intentioninformation of an interaction according to motions or speech of theuser, determine a response on the basis of the acquired intentioninformation and perform an operation.

<AI+XR>

The XR device 100 c may be implemented as a head-mount display (HMD), ahead-up display (HUD) included in a vehicle, a TV, a cellular phone, asmartphone, a computer, a wearable device, a household electricappliance, a digital signage, a vehicle, a fixed robot, or a movablerobot by employing the AI technology.

The XR device 100 c may analyze three-dimensional point cloud data orimage data acquired from an external device through various sensors andgenerate position data and attribute data with respect tothree-dimensional points to obtain information about a surrounding spaceor a real object, render an XR object to be output, and output the XRobject. For example, the XR device 100 c may output an XR objectincluding additional information about a recognized object inassociation with the recognized object.

The XR device 100 c may perform the aforementioned operations using alearning model composed of at least one artificial neural network. Forexample, the XR device 100 c can recognize a real object fromthree-dimensional point cloud data or image data using the learningmodel and provide information corresponding to the recognized realobject. Here, the learning model may be directly trained in the XRdevice 100 c or trained in an external device such as the AI server 200.

Here, although the XR device 100 c may directly generate results usingthe learning model and perform an operation, the XR device 100 c maytransmit sensor information to an external device such as the AI server200, receive results generated thereby and perform an operation.

<AI+Robot+Self-Driving>

The robot 100 a may be implemented as a guide robot, a transport robot,a cleaning robot, a wearable robot, an entertainment robot, a pet robot,an unmanned aircraft robot, or the like by employing the AI technologyand the self-driving technology.

The robot 100 a to which the AI technology and the self-drivingtechnology may refer to a robot having the self-driving function, therobot 100 a that interacts with the self-driving vehicle 100 b, or thelike.

The robot 100 a having the self-driving function may commonly refer todevices that move by themselves along given moving lines without controlof users or determine moving lines and move by themselves.

The robot 100 a having the self-driving function and the self-drivingvehicle 100 b may use a common sensing method in order to determine atleast one of a movement route and a traveling plan. For example, therobot 100 a having the self-driving function and the self-drivingvehicle 100 b can determine at least one of a movement route and atraveling plan using information sensed through a lidar, a radar and acamera.

The robot 100 a that interacts with the self-driving vehicle 100 b maybe present separately from the self-driving vehicle 100 b and perform anoperation associated with the self-driving function or a user in theself-driving vehicle 100 b inside or outside the self-driving vehicle100 b.

Here, the robot 100 a that interacts with the self-driving vehicle 100 bmay control or assist the self-driving function of the self-drivingvehicle 100 b by acquiring sensor information instead of theself-driving vehicle 100 b and providing the sensor information to theself-driving vehicle 100 b or acquiring sensor information, generatingsurrounding environment information or object information and providingthe generated information to the self-driving vehicle 100 b.

Alternatively, the robot 100 a that interacts with the self-drivingvehicle 100 b may control functions of the self-driving vehicle 100 b bymonitoring a user in the self-driving vehicle 100 b or through aninteraction with the user. For example, when it is determined that adriver is in a drowsy state, the robot 100 a may activate theself-driving function of the self-driving vehicle 100 b or assistcontrol of a driver of the self-driving vehicle 100 b. Here, functionsof the self-driving vehicle 100 b controlled by the robot 100 a mayinclude not only the self-driving function but also functions providedby a navigation system and an audio system included in the self-drivingvehicle 100 b.

Alternatively, the robot 100 a that interacts with the self-drivingvehicle 100 b may provide information to the self-driving vehicle 100 bor assist functions of the self-driving vehicle 100 b outside theself-driving vehicle 100 b. For example, the robot 100 b may providetraffic information including signal information, such as smart trafficlights, to the self-driving vehicle 100 b or automatically connect anelectric charger to a charging port by interacting with the self-drivingvehicle 100 b like an automatic electric charger of an electric vehicle.

<AI+Robot+Xr>

The robot 100 a may be implemented as a guide robot, a transport robot,a cleaning robot, a wearable robot, an entertainment robot, a pet robot,an unmanned aircraft robot, or the like by employing the AI technologyand the XR technology.

The robot 100 a to which the XR technology is applied may refer to arobot that is a control/interaction target in an XR image. In this case,the robot 100 a may be associated with the XR device 100 c while beingdistinguished from the XR device 100 c.

When the robot 100 a that is a control/interaction target in an XR imageobtains sensor information from sensors including a camera, the robot100 a or the XR device 100 c may generate an XR image based on thesensor information and the XR device 100 c may output the generated XRimage. In addition, the robot 100 a may operate on the basis of controlsignals input through the XR device 100 c or interactions of a user.

For example, the user may check an XR image corresponding to a view ofthe robot 100 a remotely associated with an external device such as theXR device 100 c, adjust a self-driving route of the robot 100 a throughan interaction, control operations or traveling, or check information onsurrounding objects.

<AI+Self-Driving+XR>

The self-driving vehicle 100 b may be implemented as a movable robot, avehicle, an unmanned aircraft, or the like by employing the AItechnology and the XR technology.

The self-driving vehicle 100 b to which the XR technology is applied mayrefer to a self-driving vehicle including a means for providing XRimages or a self-driving vehicle that is a control/interaction target inan XR image. In particular, the self-driving vehicle 100 b that is acontrol/interaction target in an XR image may be associated with the XRdevice 100 c while being distinguished from the XR device 100 c.

The self-driving vehicle 100 b including a means for providing XR imagesmay acquire sensor information from sensors including a camera andoutput XR images generated on the basis of the acquired sensorinformation. For example, the self-driving vehicle 100 b can provide anXR object corresponding to a real object or an object in an image to apassenger by including an HUD and outputting XR images.

Here, when the XR object is output through the HUD, the XR object may beoutput such that at least a part thereof is overlaid on the real objectat which the passenger gazes. On the other hand, when the XR object isoutput to a display included in the self-driving vehicle 100 b, the XRobject may be output such that at least a part thereof overlaps anobject in an image. For example, the self-driving vehicle 100 b mayoutput XR objects corresponding to objects such as roads, othervehicles, traffic lights, traffic signs, two-wheeled vehicles,pedestrians, and buildings.

When the self-driving vehicle 100 b that is a control/interaction targetin an XR image obtains sensor information from sensors including acamera, the self-driving vehicle 100 b or the XR device 100 c maygenerate an XR image based on the sensor information and the XR device100 c may output the generated XR image. In addition, the self-drivingvehicle 100 b may operate on the basis of control signals input throughan external device such as the XR device 100 c or interactions of auser.

Finally, the claims of the present disclosure may be combined in variousmanners. For example, technical features of the method claim of thepresent disclosure may be combined to implement a device, and technicalfeatures of the device claim of the present disclosure may be combinedto implement a method. In addition, the technical features of the methodclaim and the technical features of the device claim of the presentdisclosure may be combined to implement a device, and technical featuresof the method claim and the technical features of the device claim ofthe present disclosure may be combined to implement a method.

Hereinafter, physical channels and a signal transmission process will bedescribed.

FIG. 29 illustrates physical channels used in 3GPP systems and generalsignal transmission.

In a wireless communication system, a UE receives information from aneNB on downlink and transmits information to the eNB on uplink.Information transmitted/received between the eNB and the UE includesdata and various types of control information and there are variousphysical channels according to types/purposes of informationtransmitted/received by the eNB and the UE.

A UE performs initial cell search such as synchronization with an eNBwhen it is powered on or newly enters a cell (S11). To this end, the UEreceives a primary synchronization channel (PSCH) and a secondarysynchronization channel (SSCH) from the eNB to synchronize with the eNBand acquires information such as cell identity (ID). In addition, the UEmay receive a physical broadcast channel (PBCH) from the eNB to acquirebroadcast information in the cell. Further, the UE may receive adownlink reference signal (DL RS) in the initial cell search stage tocheck a downlink channel state.

Upon completion of initial cell search, the UE may receive a physicaldownlink control channel (PDCCH) and a physical downlink shared channel(PDSCH) corresponding thereto to acquire more specific systeminformation (S12).

Thereafter, the UE may perform a random access procedure to completeaccess to the eNB (S13 to S16). Specifically, the UE may transmit apreamble through a physical random access channel (PRACH) (S13) andreceive a random access response (RAR) for the preamble through thePDCCH and the PDSCH corresponding thereto (S14). Then, the UE maytransmit a physical uplink shared channel (PUSCH) using schedulinginformation in the RAR (S15) and perform a contention resolutionprocedure with respect to the PDCCH and the PDSCH corresponding thereto(S16).

Upon execution of the above-described procedures, the UE may performPDCCH/PDSCH reception (17) and PUSCH/PUCCH (Physical Uplink ControlChannel) transmission (S18) as a general uplink/downlink signaltransmission procedure. Control information transmitted from the UE tothe eNB is referred to as uplink control information (UCI). The UCIincludes hybrid automatic repeat and requestacknowledgement/negative-ACK (HARQ ACK/NACK), a scheduling request (SR),and channel state information (CSI). The CSI includes a channel qualityindicator (CQI), a precoding matrix indicator (PMI), and a rankindication (RI). Although the UCI is transmitted through a PUCCH ingeneral, it may be transmitted through a PUSCH when control informationand data need to be simultaneously transmitted. Further, the UE mayaperiodically transmit the UCI through the PUSCH in response to arequest/instruction of a network.

Hereinafter, cell search will be described.

Cell search is a procedure through which a UE acquires time andfrequency synchronization with a cell and detects a physical layer cellID of the cell. To perform cell search, the UE receives a primarysynchronization signal (PSS) and a secondary synchronization signal(SSS).

The cell search procedure of the UE cam be summarized in in Table 10.

TABLE 10 Signal type Operation Step 1 PSS SS/PBCH block (SSB) symboltiming acquisition Cell ID search in cell ID group (3 hypothesis) Step 2SSS Cell ID group detection (336 hypothesis) Step 3 PBCH DMRS SSB indexand half frame index (slot and frame boundary detection) Step 4 PBCHTime information (80 ms, SFN, SSB index, HF) RMSI CORESET/search spaceconfiguration Step 5 PDCCH and Cell access information PDSCH RACHconfiguration

FIG. 30 schematically illustrates a synchronization signal and PBCHblock (SS/PBCH block).

Referring to FIG. 30, the SS/PBCH block includes a PSS and an SSS eachoccupying one symbol and 127 subcarriers, and a PBCH occupying 3 OFDMsymbols and 240 subcarriers with an unused part for the SSS remaining onone symbol. Periodicity of the SS/PBCH block may be set by a network,and a temporal position at which the SS/PBCH block can be transmitted isdetermined by a subcarrier spacing.

Polar coding is used for the PBCH. A UE can assume a band-specificsubcarrier spacing for the SS/PBCH block unless a network sets the UEsuch that the UE assumes a different subcarrier spacing.

The PBCH symbols carry a frequency-multiplexed DMRS thereof. QPSKmodulation is used for the PBCH.

1008 unique physical layer cell IDs are given according to the followingequation 1.

N _(ID) ^(cell)=3N _(ID) ⁽¹⁾ +N _(ID) ⁽²⁾  [Equation 1]

(Here, N_(ID) ⁽¹⁾∈{0, 1, . . . , 335} and N_(ID) ⁽²⁾∈{0, 1, 2}.)

Meanwhile, a PSS sequence dsss(n) for the PSS is defined by thefollowing equation 2.

d _(PSS)(n)=1−2x(m)

m=(n+43N _(ID) ⁽²⁾)mod 127  [Equation 2]

0≤n<127

(Here, and x(i+7)=(x(i+4)+x(i))mod 2 and [x(6) x(5) x(4) x(3) x(2) x(1)x(0)]=[1 1 1 0 1 1 0].)

The aforementioned sequence can be mapped to physical resourcesillustrated in FIG. 29.

Meanwhile, an SSS sequence dsss(n) for the SSS is defined by thefollowing equation 3.

$\begin{matrix}{{d_{SSS}(n)} = {\left\lbrack {1 - {2{x_{0}\left( {\left( {n + m_{0}} \right){mod}\; 127} \right)}}} \right\rbrack{\quad\left\lbrack {{1 - {2{x_{1}\left( {\left( {n + m_{1}} \right){mod}\; 127} \right\rbrack}\mspace{79mu} m\; 0}} = {{15*{\frac{N_{ID}^{(1)}}{112}++}5N_{ID}^{(2)}\mspace{79mu} m_{1}} = {{N_{ID}^{(1)}{mod}\; 112\mspace{79mu} 0} \leq n < 127}}} \right.}}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

The aforementioned sequence can be mapped to physical resourcesillustrated in FIG. 30.

For a half frame with SS/PBCH blocks, the first symbol indexes forcandidate S S/PBCH blocks may be determined according to the subcarrierspacing of SS/PBCH bloc ks as follows.

Case A—15 kHz subcarrier spacing: the first symbols of the candidateSS/PBCH blocks have indexes of {2, 8}+14*n. For carrier frequenciessmaller than or equal to 3 GHz, n=0, 1. For carrier frequencies largerthan 3 GHz and smaller than or equal to 6 GHz, n=0, 1, 2, 3.

Case B—30 kHz subcarrier spacing: the first symbols of the candidateSS/PBCH blocks have indexes {4, 8, 16, 20}+28*n. For carrier frequenciessmaller than or equal to 3 GHz, n=0. For carrier frequencies larger than3 GHz and smaller than or equal to 6 GHz, n=0, 1.

Case C—30 kHz subcarrier spacing: the first symbols of the candidateSS/PBCH blocks have indexes {2, 8}+14*n. For carrier frequencies smallerthan or equal to 3 GHz, n=0, 1. For carrier frequencies larger than 3GHz and smaller than or equal to 6 GHz, n=0, 1, 2, 3.

Case D—120 kHz subcarrier spacing: the first symbols of the candidateSS/PBCH blocks have indexes {4, 8, 16, 20}+28*n. For carrier frequencieslarger than 6 GHz, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17,18.

Case E—240 kHz subcarrier spacing: the first symbols of the candidateSS/PBCH blocks have indexes {8, 12, 16, 20, 32, 36, 40, 44}+56*n. Forcarrier frequencies larger than 6 GHz, n=0, 1, 2, 3, 5, 6, 7, 8.

The candidate SS/PBCH blocks in a half frame may be indexed in anascending order in time from 0 to L-1. A UE needs to determine the 2LSBs, for L=4, or the 3 LSBs, for L>4, of a SS/PBCH block index per halfframe from one-to-one mapping with an index of the DM-RS sequencetransmitted in the PBCH. For L=64, the UE needs to determine the 3 MSBsof the SS/PBCH block index per half frame by PBCH payload bits ā_(Ā+5) ,ā_(Ā+6) , ā_(Ā+7) .

A UE can be configured by higher layer parameter “SSB-transmitted-SIB1”,indexes of SS/PBCH blocks for which the UE cannot receive other signalsor channels in REs that overlap with REs corresponding to the SS/PBCHblocks. A UE can also be configured per serving cell, by higher layerparameter “SSB-transmitted”, indexes of SS/PBCH blocks for which the UEcannot receive other signals or channels in REs that overlap with REscorresponding to the SS/PBCH blocks. A configuration by“SSB-transmitted” may override a configuration by“SSB-transmitted-SIB1”. A UE can be configured per serving cell byhigher layer parameter “SSB-periodicityServingCell” a periodicity of thehalf frames for reception of SS/PBCH blocks per serving cell. If the UEis not configured a periodicity of the half frames for receptions ofSS/PBCH blocks, the UE may assume a periodicity of a half frame. A UEmay assume that the periodicity is same for all SS/PBCH blocks in theserving cell.

FIG. 31 illustrates a method of acquiring timing information by a UE.

Firstly, the UE may acquire 6-bit SFN information via master informationblock (MIB) received in a PBCH. Further, the UE may acquire 4-bit SFN ina PBCH transport block.

Secondly, the UE may acquire 1-bit half frame indication as a part of aPBCH payload. For below 3 GHz, half frame indication may be furtherimplicitly signaled as a part of a PBCH DMRS for Lmax=4.

Lastly, the UE may acquire an SS/PBCH block index by a DMRS sequence andthe PBCH payload. That is, 3 LSBs of an SS block index can be acquiredby the DMRS sequence within a period of 5 ms. Further, 3 MSBs of timinginformation are carried explicitly in the PBCH payload (for above 6GHz).

For initial cell selection, a UE may assume that half frames withSS/PBCH blocks occur with a periodicity of 2 frames. Upon detection ofan SS/PBCH block, the UE determines that a control resource set forType0-PDCCH common search space is present if k_(SSB)≤23 for FR1 and ifk_(SSB)≤11 for FR2. The UE determines that a control resource set forType0-PDCCH common search space is not present if k_(SSB)>23 for FR1 andof k_(SSB)>11 for FR2.

For a serving cell without transmission of SS/PBCH blocks, a UE acquirestime and frequency synchronization with the serving cell based onreceptions of SS/PBCH blocks on the PCell, or on the PSCell, of the cellgroup for the serving cell.

Hereinafter, acquisition of system information (SI) will be described.

System information (SI) is divided into MasterInformationBlock (MIB) anda number of SystemInformationBlocks (SIBs) where:

-   -   the MIB is always transmitted on a BCH with a periodicity of 80        ms and repetitions made within 80 ms and it includes parameters        necessary to acquire SystemInformationBlockType 1 (SIB1) from        the cell;    -   SIB1 is transmitted on a DL-SCH with a periodicity and        repetitions. SIB1 includes information regarding the        availability and scheduling (e.g., periodicity, SI-window size)        of other Ms. It also indicates whether they (i.e., other SIBs)        are provided via periodic broadcast basis or only on-demand        basis. If other SIBs are provided on-demand, when SIB1 includes        information for the UE to perform SI request;    -   SIBs other than SIB1 are carried in SystemInformation (SI)        messages, which are transmitted on the DL-SCH. Each SI message        is transmitted within periodically occurring time domain windows        (referred to as SI-windows);    -   For PSCell and SCells, RAN provides the required SI by dedicated        signaling. Nevertheless, the UE needs to acquire MIB of the        PSCell to get SFN timing of the SCG (which may be different from        MCG). Upon change of relevant SI for SCell, RAN releases and        adds the concerned SCell. For PSCell, SI can only be changed        with Reconfiguration with Sync.

FIG. 32 illustrates an example of a system information acquisitionprocess of a UE.

Referring to FIG. 32, the UE may receive MIB from a network and thenreceive SIB 1. Then, the UE may transmit a system information request tothe network and receive a SystemInformation message from the network inresponse to the system information request.

The UE may apply a system information acquisition procedure to acquireaccess stratum (AS) and non-access stratum (NAS) information.

The UE in RRC_IDLE and RRC_INACTIVE states needs to ensure having avalid version of (at least) MIB, SIB1, and SystemInformationBlockTypeX(depending on support of the concerned RATs for UE controlled mobility).

The UE in RRC_CONNECTED state needs to ensure having a valid version ofMIB, SIB1, and SystemInformationBlockTypeX (depending on support ofmobility towards the concerned RATs).

The UE needs to store relevant SI acquired from the currentlycamped/serving cell. A version of the SI acquired and stored by the UEremains valid only for a certain time. The UE can use such a storedversion of the SI, for example, after cell re-selection, upon returnfrom out of coverage or after system information change indication.

Hereinafter, random access (RA) will be described.

A random access procedure of a UE can be summarized in Table 11.

TABLE 11 Signal type Operation/acquired information Step 1 PRACHpreamble of Initial beam acquisition uplink Random election ofRA-preamble ID Step 2 Random access Timing alignment informationresponse on DL-SCH RA-preamble ID Initial uplink grant, temporary C-RNTIStep 3 Uplink transmission RRC connection request on UL-SCH UEidentifier Step 4 Contention resolution C-RNTI on PDCCH for initialaccess of downlink C-RNTI on PDCCH for UE in RRC_CONNECTED state

FIG. 33 illustrates the random access procedure.

Referring to FIG. 33, firstly, a UE may transmit a PRACH preamble onuplink as message 1 (Msg1) of the random access procedure.

Random access preamble sequences of two different lengths may besupported. A long sequence having a length of 839 is applied withsubcarrier spacings of 1.25 kHz and 5 kHz and a short sequence having alength of 139 is applied with subcarrier spacings of 15, 30, 60, and 120kHz. Long sequences can support unrestricted sets and restricted sets oftype A and type B, while short sequences can support unrestricted setsonly.

Multiple RACH preamble formats may be defined with one or more RACH OFDMsymbols, and different cyclic prefixes (CPs), and a guard time. ThePRACH preamble configuration to use may be provided to the UE in thesystem information.

When there is no response to Msg1, the UE may retransmit the PRACHpreamble with power ramping within a predetermined number of times. TheUE calculates PRACH transmission power for retransmission of thepreamble on the basis of the most recent estimate pathloss and a powerramping counter. If the UE conducts beam switching, the power rampingcounter remains unchanged.

FIG. 34 illustrates the power ramping counter.

The UE can perform power ramping for retransmission of a random accesspreamble on the basis of the power ramping counter. Here, the powerramping counter remains unchanged when the UE performs beam switchingduring PRACH retransmission, as described above.

Referring to FIG. 34, when the UE retransmits a random access preamblefor the same beam as in a case where the power ramping counter increasesfrom 1 to 2 and from 3 to 4, the UE increases the power ramping counterby 1. However, when the beam has changed, the power ramping counter maynot change during PRACH retransmission.

FIG. 35 illustrates the concept of a threshold of SS blocks for RACHresource association.

System information informs the UE of the association between SS blocksand RACH resources. The threshold of the SS blocks for RACH resourceassociation may be based on the RSRP and network configurable.Transmission or retransmission of a RACH preamble may be based on SSblocks that satisfy the threshold. Accordingly, in the example of FIG.35, SS block m exceeds the threshold of received power, and thus theRACH preamble is transmitted or retransmitted on the basis of SS blockm.

Thereafter, when the UE receives a random access response on a DL-SCH,the DL-SCH may provide timing alignment information, a RA-preamble ID,an initial uplink grant, and a temporary C-RNTI.

Based on this information, the UE may perform uplink transmission on aUL-SCH as message 3 (Msg3) of the random access procedure. Msg3 mayinclude an RRC connection request and a UE ID.

In response, the network may transmit Msg4, which can be treated as acontention resolution message on downlink. The UE can enter an RRCconnected state by receiving Msg4.

Hereinafter, the random access procedure will be described in moredetail.

Prior to initiation of a physical random access procedure, Layer 1 needsto receive a set of SS/PBCH block indexes from high layers and provide acorresponding set of RSRP measurements to the higher layers.

Prior to initiation of the physical random access procedure, Layer 1needs to receive the following information from the higher layers.

-   -   Configuration of PRACH transmission parameters (a PRACH preamble        format, time resources, and frequency resources for PRACH        transmission)    -   Parameters for determining root sequences and their cyclic        shifts in a PRACH preamble sequence set (index to logical root        sequence table, cyclic shift (N_(cs)), and set type (an        unrestricted set, restricted set A, and restricted set B)).

From the physical layer perspective, L1 random access procedureencompasses transmission of a random access preamble (Msg1) in a PRACH,a random access response (RAR) message (Msg2) with a PDCCH/PDSCH, andwhen applicable, transmission of Msg3 PUSCH, and PDSCH for contentionresolution.

If a random access procedure is initiated by a PDCCH order to the UE,random access preamble transmission may be with the same subcarrierspacing as a subcarrier spacing for random access preamble transmissioninitiated by higher layers.

If a UE is configured with two uplink carriers for a serving cell andthe UE detects a PDCCH order, the UE may use a UL/SUL indicator fieldvalue from the detected PDCCH order to determine an uplink carrier forthe corresponding random access preamble transmission.

Hereinafter, the random access preamble will be described in moredetail.

Regarding the random access preamble transmission step, the physicalrandom access procedure may be triggered upon request of a PRACHtransmission by higher layers or by a PDCCH order. A configuration byhigher layers for PRACH transmission may include the following.

-   -   A configuration for PRACH transmission    -   A preamble index, a preamble subcarrier spacing,        P_(PRACH,target), a corresponding RA-RNTI, and a PRACH resources

A preamble may be transmitted using a selected PRACH format with atransmission power P_(PRACH,b,f,c(i)) on the indicated PRACH resources.

A UE may be provided with a number of SS/PBCH blocks associated with onePRACH occasion by a value of a higher layer parameterSSB-perRACH-Occasion. If the value of SSB-perRACH-Occasion is less than1, one SS/PBCH block can be mapped to consecutive PRACH occasions of1/SSB-perRACH-Occasions. The UE may be provided with a number ofpreambles per SS/PBCH by the value of higher layer parametercb-preamblePerSSB, and the UE may determine a total number of preamblesper SSB per PRACH occasion as a multiple of the value ofSSB-perRACH-Occasion and the value of cb-preamblePerSSB.

SS/PBCH block indexes may be mapped to PRACH occasions in the followingorders.

-   -   First, in ascending order of preamble indexes within a single        PRACH occasion    -   Second, in ascending order of frequency resource indexes for        frequency multiplexed PRACH occasions    -   Third, in ascending order of time resource indexes for time        multiplexed PRACH occasions within a PRACH slot    -   Fourth, in ascending order of indexes for PRACH slots

A period starting from frame 0, for mapping of SS/PBCH blocks to PRACHoccasions, is the smallest of PRACH configuration periods {1, 2, 4}equal to or greater than (N_(Tx) ^(SSB)/N_(PRACHperiod) ^(SSB)), wherethe UE acquires N^(SSB) _(Tx) from higher layer parameterSSB-transmitted-SIB1, and N^(SSB) _(PRACHperiod) is the number ofSS/PBCH blocks that can be mapped to one PRACH configuration period.

If a random access procedure is initiated by a PDCCH order, the UE needsto, if requested by higher layers, transmit a PRACH in the firstavailable PRACH occasion for which a time between the last symbol of thePDCCH order reception and the first symbol of the PRACH transmission isequal to or longer than N_(T,2)+Δ_(BWPSwitching)+Δ_(Delay) msec, whereN_(T,2) is a time duration of N2 symbols corresponding to a PUSCHpreparation time for PUSCH processing capability 1, Δ_(BWPSwitching) ispredefined, and Δ_(Delay)>0.

Hereinafter, the random access response will be described in moredetail.

In response to a PRACH transmission, a UE attempts to detect a PDCCHwith a corresponding RA-RNTI during a window controlled by higherlayers. The window may start at the first symbol of the earliest controlresource set the UE is configured for Typel-PDCCH common search spacethat is at least ((ΔΕN_(slot) ^(subframe,μ)ΕN_(symb) ^(slot))/T_(sf))symbols after the last symbol of preamble sequence transmission. Thelength of the window in number of slots, based on the subcarrier spacingfor Type0-PDCCH common search space may be provided by higher layerparameter rar-WindowLength.

If a UE detects a PDCCH with the corresponding RA-RNTI and acorresponding PDSCH including a DL-SCH transport block within thewindow, the UE can pass the transport block to higher layers. The higherlayers can parse the transport block for a random access preambleidentity (RAPID) associated with the PRACH transmission. If the higherlayers identify the RAPID in RAR message(s) of the DL-SCH transportblock, the higher layers can indicate an uplink grant to the physicallayer. This may be referred to as a random access response (RAR) uplinkgrant in the physical layer. If the higher layers do not identify theRAPID associated with the PRACH transmission, the higher layers canindicate to the physical layer to transmit a PRACH. A minimum timebetween the last symbol of the PDSCH reception and the first symbol ofthe PRACH transmission is equal to N_(T,1)+Δ_(new)+0.5, where N_(T,1) isa time duration of N₁ symbols corresponding to a PDSCH reception timefor PDSCH processing capability 1 and Δ_(new)≥0.

A UE may need to receive the PDCCH with the corresponding RA-RNTI andthe corresponding PDSCH including a DL-SCH transport block with the sameDM-RS antenna port quasi co-location (QCL) properties, as for a detectedSS/PBCH block or a received CSI-RS. If the UE attempts to detect thePDCCH with the corresponding RA-RNTI in response to a PRACH transmissioninitiated by a PDCCH order, the UE may assume that the PDCCH and thePDCCH order have the same DM-RS antenna port QCL properties.

A RAR uplink grant schedules a PUSCH transmission from the UE (Msg3PUSCH). The contents of the RAR uplink grant, starting with the MSB andending with the LSB, are given in Table 12. Table 12 shows a randomaccess response grant configuration field size.

TABLE 12 RAR grant field Number of bits Frequency hopping flag 1 Msg3PUSCH frequency resource allocation 14 Msg3 PUSCH time resourceallocation 4 MCS 4 TPC command for Msg3 PUSCH 3 CSI request 1 Reservedbits 3

Msg3 PUSCH frequency resource allocation is for uplink resourceallocation type 1. In case of frequency hopping, based on the indicationof the frequency hopping flag, the first one or two bits N_(UL,hop) ofthe Msg3 PUSCH frequency resource allocation field can be used ashopping information bits. The MCS can be determined from the first 16indexes of the available MCS index table for the PUSCH.

The TPC command δ_(msg2, b,f,c) is used to set the power of the Msg3PUSCH and may be interpreted according to the following table 13.

TABLE 13 TPC Command Value [dB] 0 −6 1 −4 2 −2 3 0 4 2 5 4 6 6 7 8

In a non-contention-based random access procedure, the CSI request fieldis interpreted to determine whether an aperiodic CSI report is includedin the corresponding PUSCH transmission. In a contention-based randomaccess procedure, the CSI request field may be reserved. Unless a UE isconfigured a subcarrier spacing, the UE receives a subsequent PDSCHusing the same subcarrier spacing as that for PDSCH reception whichprovides a RAR message.

If a UE does not detect the PDCCH with a corresponding RA-RNTI and acorresponding DL-SCH transport block within the window, the UE performsa procedure for random access response reception failure.

Hereinafter, Msg3 PUSCH transmission will be described in more detail.

Regarding Msg3 PUSCH transmission, higher layer parameter msg3-tpindicates to the UE whether or not the UE applies transform precoding,for Msg3 PUSCH transmission. If the UE applies transform precoding toMsg3 PUSCH transmission with frequency hopping, a frequency offset forthe second hop may be given in Table 14. Table 14 shows frequencyoffsets for the second hop for Msg3 PUSCH transmission with frequencyhopping.

TABLE 14 Number of PRBs in Value of N_(UL, hop) Frequency offset initialactive UL BWP Hopping Bits for 2^(nd) hop N^(size) _(BWP) < 50 0N^(size) _(BWP)/2 1 N^(size) _(BWP)/4 N^(size) _(BWP) ≥ 50 00 N^(size)_(BWP)/2 01 N^(size) _(BWP)/4 10 −N^(size) _(BWP)/4 11 Reserved

The subcarrier spacing for Msg3 PUSCH transmission may be provided by ahigher layer parameter msg3-scs. The UE needs to transmit a PRACH andMsg3 PUSCH on the same uplink carrier of the same serving cell. A UL BWPfor Msg3 PUSCH transmission may be indicated bySystemInformationBlockType1. A minimum time between the last symbol ofPDSCH reception conveying a RAR and the first symbol of correspondingMsg3 PUSCH transmission scheduled by the RAR in a PDSCH for the UE whenthe PDSCH and the PUSCH have the same subcarrier spacing may be equal toN_(T,1)+N_(T,2)+N_(TA,max)+0.5 msec. N_(T,1) is a time duration of N₁symbols corresponding to PDSCH reception time for PDSCH processingcapability 1 when an additional PDSCH DM-RS is configured, N_(T,2) is atime duration of N2 symbols corresponding to PUSCH preparation time forPUSCH processing capability 1, N_(TA,MAX) is a maximum timing adjustmentvalue that can be provided by the TA command field in the RAR.

Hereinafter, contention resolution will be described in more detail.

In response to an Msg3 PUSCH transmission when a UE has not beenprovided with a C-RNTI, the UE attempts to detect a PDCCH with acorresponding TC-RNTI scheduling a PDSCH that includes a UE contentionresolution identity. In response to the PDSCH reception with the UEcontention resolution identity, the UE transmits HARQ-ACK information ina PUCCH. A minimum time between the last symbol of the PDSCH receptionand the first symbol of the corresponding HARQ-ACK transmission is equalto N_(T,1)+0.5 msec. N_(T,1) is a time duration of N₁ symbolscorresponding to a PDSCH reception time for PDSCH processing capability1 when additional PDSCH DM-RS is configured.

Hereinafter, channel coding scheme will be described.

Channel coding schemes according to one embodiment of the presentdisclosure may mainly include a low density parity check (LDPC) codingscheme for data, and a polar coding scheme for control information.

A network/UE may perform LDPC coding on a PDSCH/PUSCH with two basegraph (BG) support. Here, BG1 is for mother code rate 1/3, and BG2 isfor mother code rate 1/5.

For coding of control information, repetition coding/simplexcoding/Reed-Muller coding can be supported. The polar coding scheme canbe used for the case when the control information has a length longerthan 11 bits. A mother code size may be 512 for DL and may be 1024 forUL. Coding schemes for uplink control information can be summarized inthe following table.

TABLE 15 Uplink Control Information size including CRC, if presentChannel code 1 Repetition code 2 Simplex code 3-11 Reed Muller code >11 Polar code

The polar coding scheme may be used for a PBCH. This coding scheme maybe the same as that for the PDCCH. Hereinafter, an LDPC coding structurewill be described.

LDPC code is a (n, k) linear block code defined as a null-space of a(n−k)×n sparse parity check matrix H.

LDPC code applicable to some embodiments of the present disclosure maybe as follows.

$\begin{matrix}{{H_{x}^{T} = 0}{H_{X}^{T} = {{\begin{bmatrix}1 & 1 & 1 & 0 & 0 \\1 & 0 & 0 & 1 & 1 \\1 & 1 & 0 & 0 & 0 \\0 & 1 & 1 & 1 & 0\end{bmatrix}\begin{bmatrix}x_{1} \\x_{2} \\x_{3} \\x_{4} \\x_{5}\end{bmatrix}} = \begin{bmatrix}0 \\0 \\0 \\0\end{bmatrix}}}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack\end{matrix}$

FIG. 36 illustrates a parity check matrix represented by a protograph.

Specifically, FIG. 36 illustrates a parity check matrix with respect toassociation between variable nodes and check nodes, represented by aprotograph.

For example, referring to FIG. 36, variable nodes associated with acheck node c₁ are v₁, v₂, v₃, v₄, v₆, and v₇, and check nodes associatedwith a variable node v₈ are c₂, c₃, and c₄.

FIG. 37 illustrates an example of an encoder structure for polar code.Specifically, (a) of FIG. 37 illustrates an example of a base module forpolar code, and (b) of FIG. 37 illustrates a base matrix.

The polar code is known in the art as a code which can acquire channelcapacity in a binary-input discrete memoryless channel (B-DMC). That is,channel capacity can be acquired when the size N of the code block isincreased to infinite.

FIG. 38 schematically illustrates an example of an encoder operation forthe polar code.

Referring to FIG. 38, a polar code encoder can perform channelcombination and channel splitting. Specifically, the polar code encodercan combine original channels into one vector channel of split onevector channel into multiple new channels. For example, originalchannels before being combined into one vector channel may be uniform,and multiple new channels split from one vector channel may bepolarized.

<Discontinuous Reception (DRX)>

Discontinuous reception (DRX) means an operation mode in which userequipment (UE) can discontinuously receive a downlink channel byreducing battery consumption. That is, a UE for which DRX is configuredcan reduce power consumption by discontinuously receiving a DL signal.

The DRX operation is performed within a DRX cycle representing a timeinterval at which on-duration is periodically repeated. The DRX cycleincludes on-duration and sleep duration (or DRX occasion). On-durationrepresents a time interval in which a UE monitors a PDCCH in order toreceive a PDCCH.

DRX can be performed in RRC (Radio Resource Control)_IDLE state (ormode), RRC_INACTIVE state (or mode) or RRC_CONNECTED state (or mode). InRRC_IDLE state and RRC_INACTIVE state, DRX can be used todiscontinuously receive a paging signal.

-   -   RRC_IDLE state: a state in which radio connection (RRC        connection) between an eNB and a UE is not established.    -   RRC_INACTIVE state: a state in which radio connection (RRC        connection) between an eNB and a UE is established but radio        connection is deactivated.    -   RRC_CONNECTED state: a state in which radio connection (RRC        connection) between an eNB and a UE is established.

DRX can be basically divided into idle mode DRX, connected DRX (C-DRX),and extended DRX.

DRX applied in an IDLE state may be referred to as idle mode DRX, andDRX applied in a CONNECTED state may be referred to as connected DRX(C-DRX).

eDRX (Extended/Enhanced DRX) is a mechanism for extending cycles of theidle mode DRX and C-DRX and may be mainly used for application of(massive) IoT. In idle mode DRX, whether to allow eDRX can be set on thebasis of system information (e.g., SIB1). SIB1 may include aneDRX-allowed parameter. eDRX-allowed parameter indicates whether idlemode extended DRX is allowed.

<Idle Mode DRX>

In the idle mode, a UE can use DRX to reduce power consumption. Onepaging occasion (PO) is a subframe in which a P-RNTI (Paging-RadioNetwork Temporary Identifier) can be transmitted through a PDCCH (thataddresses a paging message for NB-IoT), an MPDCCH (MTC PDCCH) or anNPDCCH (Narrowband PDCCH).

In the P-RNTI transmitted through the MPDCCH, the PO can represent thestarting subframe of MPDCCH repetition. In case of the P-RNTItransmitted through the NPDCCH, when a subframe determined by the PO isnot valid NB-IoT downlink subframe, the PO can represent the startingsubframe of NPDCCH repetition. Accordingly, the first valid NB-IoTdownlink subframe after the PO is the starting subframe of NPDCCHrepetition.

One paging frame (PF) is one radio frame that can include one or morepaging occasions. When DRX is used, a UE can monitor only one PO per DRXcycle. One paging narrow band (PNB) is a narrow band in which a UEperforms paging message reception. PF, PO, and PNB can be determined onthe basis of DRX parameters provided by system information.

FIG. 39 is a flowchart illustrating an example of performing an idlemode DRX operation.

Referring to FIG. 39, a UE may receive idle mode DRX configurationinformation from a base station through higher layer signaling (e.g.,system information) (S21).

The UE may determine a paging frame (PF) and a paging occasion (PO) inorder to monitor a PDCCH in a paging DRX cycle on the basis of the idlemode DRX configuration information (S22). In this case, the DRX cyclemay include on-duration and sleep duration (or DRX occasion).

The UE may monitor the PDCCH in the PO of the determined PF (S23). Here,the UE monitors only one subframe (PO) per paging DRX cycle, forexample. Further, upon reception of a PDCCH scrambled by a P-RNTI foron-duration (i.e., upon detection of paging), the UE can switch to aconnected mode and transmit/receive data to/from the base station.

FIG. 40 schematically illustrates an example of the idle mode DRXoperation.

Referring to FIG. 40, when there is traffic directed to a UE in RRC_IDLEstate (hereinafter referred to as a “idle state”), paging for the UEoccurs. The UE can wake up periodically (i.e., at (paging) DRX cycle) tomonitor a PDCCH. When paging is not present, the UE can switch to aconnected state to receive data, and when data is not present, enter asleep mode.

<Connected Mode DRX (C-DRX))>

C-DRX refers to DRX applied in RRC_CONNECTED state. The DRX cycle ofC-DRX can be composed of a short DRX cycle and/or a long DRX cycle.Here, the short DRX cycle may be an option.

When C-DRX is configured, a UE can perform PDCCH monitoring foron-duration. When a PDCCH is successfully detected during PDCCHmonitoring, the UE can operate (or execute) an inactive timer and remainin an awake state. On the other hand, when a PDCCH is not successfullydetected during PDCCH monitoring, the UE can enter a sleep state afteron-duration ends.

When C-DRX is configured, PDCCH reception occasions (e.g., slots havinga PDCCH search space) may be discontinuously configured based on C-DRXconfiguration. On the contrary, when C-DRX is not configured, PDCCHreception occasions (e.g., slots having a PDCCH search space) can becontinuously configured in the present disclosure.

Meanwhile, PDCCH monitoring may be limited to a time interval set to ameasurement gap irrespective of C-DRX configuration.

FIG. 41 is a flowchart illustrating an example of a method of performinga C-DRX operation.

A UE may receive RRC signaling (e.g., MAC-MainConfig IE) including DRXconfiguration information from a base station (S31).

Here, the DRX configuration information may include the followinginformation.

-   -   onDurationTimer: the number of PDCCH subframes that can be        continuously monitored at the start of a DRX cycle    -   drx-InactivityTimer: the number of PDCCH subframes that can be        continuously monitored when a UE decodes a PDCCH having        scheduling information    -   drx-RetransmissionTimer: the number of PDCCH subframes to be        continuously monitored when HARQ retransmission is expected    -   longDRX-Cycle: on-duration occurrence period    -   drxStartOffset: a subframe number at which a DRX cycle starts    -   drxShortCycleTimer: a short DRX cycle number    -   shortDRX-Cycle: a DRX cycle operating by the number of        drxShortCycleTimer when Drx-InactivityTimer expires

In addition, when DRX “ON” is configured through a DRX command of a MACcommand element (CE) (S32), the UE monitors a PDCCH for on-duration ofthe DRX cycle on the basis of DRX configuration (S33).

FIG. 42 schematically illustrates an example of the C-DRX operation.

When a UE receives scheduling information (e.g., a DL grant) inRRC_CONNECTED state (hereinafter referred to as a connected state), theUE can execute an inactive timer and an RRC inactive timer.

When the DRX inactive timer expires, a DRX mode can be initiated. The UEcan wake up in the DRX cycle and monitor a PDCCH for a predeterminedtime (on a duration timer).

In this case, when short DRX is configured, the UE initiates the DRXmode with a short DRX cycle first, and after the short DRX cycle ends,initiates the DRX mode with a long DRX cycle. Here, the long DRX cyclemay correspond to a multiple of the short DRX cycle. In addition, the UEcan wake up more frequently in the short cycle. After the RRC inactivetimer expires, the UE can switch to an IDLE state and perform an idlemode DRX operation.

<Ia/Ra+Drx Operation>

FIG. 43 schematically illustrates an example of power consumption inresponse to a UE state.

Referring to FIG. 43, After a UE is powered on, the UE performs boot upfor application loading, an initial access/random access procedure fordownlink and uplink synchronization with a base station, and a networkregistration procedure. Here, current consumption (power consumption)during each procedure is shown in FIG. 42.

If transmission power of the UE is high, current consumption of the UEmay increase. Further, when traffic that needs to be transmitted to a UEor traffic that needs to be transmitted to a base station is notpresent, the UE switches to the idle mode in order to reduce powerconsumption and performs the idle mode DRX operation.

When paging (e.g., call) is generated during the idle mode DRXoperation, the UE can switch from the idle mode to the connected modethrough a cell establishment procedure and transmit/receive data to/fromthe base station.

In addition, when there is no data received from the base station ortransmitted to the base station for a specific time in the connectedmode or at set timing, the UE can perform connected DRX (C-DRX).

Furthermore, when extended DRX (eDRX) is configured for the UE throughhigher layer signaling (e.g., system information), the UE can performeDRX operation in the idle mode or connected mode.

1-15. (canceled)
 16. A method for performing a physical uplink sharedchannel (PUSCH) transmission in a wireless communication system, themethod performed by a user equipment (UE) and comprising: receiving adiscontinuous reception (DRX) configuration from the base station;monitoring a physical downlink control channel (PDCCH) during anon-duration of a DRX cycle based on the DRX configuration; andperforming the PUSCH transmission based on monitoring the PDCCH, whereinthe UE receives information for a start symbol of the PUSCHtransmission, wherein the UE performs the PUSCH transmission based onthe start symbol, wherein a cyclic prefix (CP) extension is presentedduring a specific interval preceding the start symbol of the PUSCHtransmission, and wherein the specific interval is determined based onfirst information and second information.
 17. The method of claim 16,wherein the first information is a value of one of 25*10{circumflex over( )}(−6), 16*10{circumflex over ( )}(−6)+T_TA or 25*10{circumflex over( )}(−6)+T_TA, wherein the T_TA is a timing advance between a downlinkand an uplink.
 18. The method of claim 17, wherein the secondinformation is a value related to a subcarrier spacing.
 19. The methodof claim 18, wherein the UE receives information related to a listenbefore transmission (LBT) type.
 20. The method of claim 19, wherein theinformation related to the LBT type is information related to a type ofa channel sensing used before the UE transmits a signal.
 21. The methodof claim 20, wherein the first information and the second informationare determined based on the LBT type.
 22. The method of claim 16,wherein the start symbol is informed based on start and length indicatorvalue (SLIV) information.
 23. The method of claim 22, wherein the SLIVinformation informs a start symbol index of the PUSCH and a number ofsymbols constituting the PUSCH.
 24. A user equipment (UE) comprising: amemory; a transceiver; and a processor operatively coupled to the memoryand the transceiver, wherein the processor is configured to: control thetransceiver to receive a discontinuous reception (DRX) configurationfrom the base station; monitor a physical downlink control channel(PDCCH) during an on-duration of a DRX cycle based on the DRXconfiguration; and perform the PUSCH transmission based on monitoringthe PDCCH, wherein the UE receives information for a start symbol of thePUSCH transmission, wherein the UE performs the PUSCH transmission basedon the start symbol, wherein a cyclic prefix (CP) extension is presentedduring a specific interval preceding the start symbol of the PUSCHtransmission, and wherein the specific interval is determined based onfirst information and second information.